diff --git a/bower.json b/bower.json
index 369ad240..9c5feddd 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,6 @@
 {
   "name": "aurelia-binding",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "description": "A modern databinding library for JavaScript and HTML.",
   "license": "MIT",
   "keywords": [
diff --git a/dist/amd/aurelia-binding.js b/dist/amd/aurelia-binding.js
index 69e46fde..7bb8220b 100644
--- a/dist/amd/aurelia-binding.js
+++ b/dist/amd/aurelia-binding.js
@@ -1920,21 +1920,12 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
     return LiteralObject;
   }(Expression);
 
-  var evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
   function evalList(scope, list, lookupFunctions) {
     var length = list.length;
-
-    for (var cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-      evalListCache.push([]);
-    }
-
-    var result = evalListCache[length];
-
-    for (var _i14 = 0; _i14 < length; ++_i14) {
+    var result = [];
+    for (var _i14 = 0; _i14 < length; _i14++) {
       result[_i14] = list[_i14].evaluate(scope, lookupFunctions);
     }
-
     return result;
   }
 
@@ -3017,7 +3008,7 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
         if (this.optional('.')) {
           name = this.peek.key;
           this.advance();
-        } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+        } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}' || this.peek.text === ',') {
           return new AccessThis(ancestor);
         } else {
           this.error('Unexpected token ' + this.peek.text);
@@ -3698,6 +3689,16 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
       return this.element.style.cssText;
     };
 
+    StyleObserver.prototype._setProperty = function _setProperty(style, value) {
+      var priority = '';
+
+      if (value.indexOf('!important') !== -1) {
+        priority = 'important';
+        value = value.replace('!important', '');
+      }
+      this.element.style.setProperty(style, value, priority);
+    };
+
     StyleObserver.prototype.setValue = function setValue(newValue) {
       var styles = this.styles || {};
       var style = void 0;
@@ -3708,7 +3709,7 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
           for (style in newValue) {
             if (newValue.hasOwnProperty(style)) {
               styles[style] = version;
-              this.element.style[style] = newValue[style];
+              this._setProperty(style, newValue[style]);
             }
           }
         } else if (newValue.length) {
@@ -3721,7 +3722,7 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
             }
 
             styles[style] = version;
-            this.element.style[style] = pair[2];
+            this._setProperty(style, pair[2]);
           }
         }
       }
@@ -3739,7 +3740,7 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
           continue;
         }
 
-        this.element.style[style] = '';
+        this.element.style.removeProperty(style);
       }
     };
 
@@ -4601,7 +4602,7 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
         if (xlinkResult) {
           return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
         }
-        if (/^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof _aureliaPal.DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
+        if (propertyName === 'role' && (obj instanceof _aureliaPal.DOM.Element || obj instanceof _aureliaPal.DOM.SVGElement) || /^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof _aureliaPal.DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
           return new DataAttributeObserver(obj, propertyName);
         }
       }
@@ -5304,7 +5305,8 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
 
   function observable(targetOrConfig, key, descriptor) {
     function deco(target, key, descriptor, config) {
-      if (key === undefined) {
+      var isClassDecorator = key === undefined;
+      if (isClassDecorator) {
         target = target.prototype;
         key = typeof config === 'string' ? config : config.name;
       }
@@ -5321,6 +5323,10 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
         descriptor = {};
       }
 
+      if (!('enumerable' in descriptor)) {
+        descriptor.enumerable = true;
+      }
+
       delete descriptor.writable;
       delete descriptor.initializer;
 
@@ -5337,7 +5343,11 @@ define(['exports', 'aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aure
 
       descriptor.get.dependencies = [innerPropertyName];
 
-      Reflect.defineProperty(target, key, descriptor);
+      if (isClassDecorator) {
+        Reflect.defineProperty(target, key, descriptor);
+      } else {
+        return descriptor;
+      }
     }
 
     if (key === undefined) {
diff --git a/dist/aurelia-binding.d.ts b/dist/aurelia-binding.d.ts
index 958aa66b..e87a22dd 100644
--- a/dist/aurelia-binding.d.ts
+++ b/dist/aurelia-binding.d.ts
@@ -184,6 +184,11 @@ export declare interface InternalPropertyObserver {
   unsubscribe(context: any, callable: Callable): void;
 }
 
+/**
+ * Property observer for HTML Attributes.
+ */
+export declare class DataAttributeObserver implements InternalPropertyObserver {}
+
 /**
  * Observes collection mutation.
  */
diff --git a/dist/aurelia-binding.js b/dist/aurelia-binding.js
index c4b2177a..994a717d 100644
--- a/dist/aurelia-binding.js
+++ b/dist/aurelia-binding.js
@@ -1769,22 +1769,13 @@ export class LiteralObject extends Expression {
   }
 }
 
-let evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
 /// Evaluate the [list] in context of the [scope].
 function evalList(scope, list, lookupFunctions) {
-  let length = list.length;
-
-  for (let cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-    evalListCache.push([]);
-  }
-
-  let result = evalListCache[length];
-
-  for (let i = 0; i < length; ++i) {
+  const length = list.length;
+  const result = [];
+  for (let i = 0; i < length; i++) {
     result[i] = list[i].evaluate(scope, lookupFunctions);
   }
-
   return result;
 }
 
@@ -2889,7 +2880,12 @@ export class ParserImplementation {
       if (this.optional('.')) {
         name = this.peek.key;
         this.advance();
-      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+      } else if (this.peek === EOF
+        || this.peek.text === '('
+        || this.peek.text === '['
+        || this.peek.text === '}'
+        || this.peek.text === ','
+      ) {
         return new AccessThis(ancestor);
       } else {
         this.error(`Unexpected token ${this.peek.text}`);
@@ -3512,6 +3508,16 @@ export class StyleObserver {
     return this.element.style.cssText;
   }
 
+  _setProperty(style, value) {
+    let priority = '';
+
+    if (value.indexOf('!important') !== -1) {
+      priority = 'important';
+      value = value.replace('!important', '');
+    }
+    this.element.style.setProperty(style, value, priority);
+  }
+
   setValue(newValue) {
     let styles = this.styles || {};
     let style;
@@ -3522,7 +3528,7 @@ export class StyleObserver {
         for (style in newValue) {
           if (newValue.hasOwnProperty(style)) {
             styles[style] = version;
-            this.element.style[style] = newValue[style];
+            this._setProperty(style, newValue[style]);
           }
         }
       } else if (newValue.length) {
@@ -3533,7 +3539,7 @@ export class StyleObserver {
           if ( !style ) { continue; }
 
           styles[style] = version;
-          this.element.style[style] = pair[2];
+          this._setProperty(style, pair[2]);
         }
       }
     }
@@ -3551,7 +3557,7 @@ export class StyleObserver {
         continue;
       }
 
-      this.element.style[style] = '';
+      this.element.style.removeProperty(style);
     }
   }
 
@@ -4357,7 +4363,8 @@ export class ObserverLocator {
       if (xlinkResult) {
         return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
       }
-      if (/^\w+:|^data-|^aria-/.test(propertyName)
+      if (propertyName === 'role' && (obj instanceof DOM.Element || obj instanceof DOM.SVGElement)
+        || /^\w+:|^data-|^aria-/.test(propertyName)
         || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
         return new DataAttributeObserver(obj, propertyName);
       }
@@ -5025,7 +5032,8 @@ class ModifySetObserver extends ModifyCollectionObserver {
 export function observable(targetOrConfig: any, key: string, descriptor?: PropertyDescriptor) {
   function deco(target, key, descriptor, config) { // eslint-disable-line no-shadow
     // class decorator?
-    if (key === undefined) {
+    const isClassDecorator = key === undefined;
+    if (isClassDecorator) {
       target = target.prototype;
       key = typeof config === 'string' ? config : config.name;
     }
@@ -5044,8 +5052,14 @@ export function observable(targetOrConfig: any, key: string, descriptor?: Proper
         target[innerPropertyName] = descriptor.initializer();
       }
     } else {
+      // there is no descriptor if the target was a field in TS (although Babel provides one),
+      // or if the decorator was applied to a class.
       descriptor = {};
     }
+    // make the accessor enumerable by default, as fields are enumerable
+    if (!('enumerable' in descriptor)) {
+      descriptor.enumerable = true;
+    }
 
     // we're adding a getter and setter which means the property descriptor
     // cannot have a "value" or "writable" attribute
@@ -5066,7 +5080,11 @@ export function observable(targetOrConfig: any, key: string, descriptor?: Proper
     // dependencies. This is the equivalent of "@computedFrom(...)".
     descriptor.get.dependencies = [innerPropertyName];
 
-    Reflect.defineProperty(target, key, descriptor);
+    if (isClassDecorator) {
+      Reflect.defineProperty(target, key, descriptor);
+    } else {
+      return descriptor;
+    }
   }
 
   if (key === undefined) {
diff --git a/dist/commonjs/aurelia-binding.js b/dist/commonjs/aurelia-binding.js
index 13c36a93..c000d7e3 100644
--- a/dist/commonjs/aurelia-binding.js
+++ b/dist/commonjs/aurelia-binding.js
@@ -1873,21 +1873,12 @@ var LiteralObject = exports.LiteralObject = function (_Expression18) {
   return LiteralObject;
 }(Expression);
 
-var evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
 function evalList(scope, list, lookupFunctions) {
   var length = list.length;
-
-  for (var cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-    evalListCache.push([]);
-  }
-
-  var result = evalListCache[length];
-
-  for (var _i14 = 0; _i14 < length; ++_i14) {
+  var result = [];
+  for (var _i14 = 0; _i14 < length; _i14++) {
     result[_i14] = list[_i14].evaluate(scope, lookupFunctions);
   }
-
   return result;
 }
 
@@ -2970,7 +2961,7 @@ var ParserImplementation = exports.ParserImplementation = function () {
       if (this.optional('.')) {
         name = this.peek.key;
         this.advance();
-      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}' || this.peek.text === ',') {
         return new AccessThis(ancestor);
       } else {
         this.error('Unexpected token ' + this.peek.text);
@@ -3651,6 +3642,16 @@ var StyleObserver = exports.StyleObserver = function () {
     return this.element.style.cssText;
   };
 
+  StyleObserver.prototype._setProperty = function _setProperty(style, value) {
+    var priority = '';
+
+    if (value.indexOf('!important') !== -1) {
+      priority = 'important';
+      value = value.replace('!important', '');
+    }
+    this.element.style.setProperty(style, value, priority);
+  };
+
   StyleObserver.prototype.setValue = function setValue(newValue) {
     var styles = this.styles || {};
     var style = void 0;
@@ -3661,7 +3662,7 @@ var StyleObserver = exports.StyleObserver = function () {
         for (style in newValue) {
           if (newValue.hasOwnProperty(style)) {
             styles[style] = version;
-            this.element.style[style] = newValue[style];
+            this._setProperty(style, newValue[style]);
           }
         }
       } else if (newValue.length) {
@@ -3674,7 +3675,7 @@ var StyleObserver = exports.StyleObserver = function () {
           }
 
           styles[style] = version;
-          this.element.style[style] = pair[2];
+          this._setProperty(style, pair[2]);
         }
       }
     }
@@ -3692,7 +3693,7 @@ var StyleObserver = exports.StyleObserver = function () {
         continue;
       }
 
-      this.element.style[style] = '';
+      this.element.style.removeProperty(style);
     }
   };
 
@@ -4554,7 +4555,7 @@ var ObserverLocator = exports.ObserverLocator = (_temp = _class11 = function ()
       if (xlinkResult) {
         return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
       }
-      if (/^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof _aureliaPal.DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
+      if (propertyName === 'role' && (obj instanceof _aureliaPal.DOM.Element || obj instanceof _aureliaPal.DOM.SVGElement) || /^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof _aureliaPal.DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
         return new DataAttributeObserver(obj, propertyName);
       }
     }
@@ -5257,7 +5258,8 @@ var ModifySetObserver = function (_ModifyCollectionObse3) {
 
 function observable(targetOrConfig, key, descriptor) {
   function deco(target, key, descriptor, config) {
-    if (key === undefined) {
+    var isClassDecorator = key === undefined;
+    if (isClassDecorator) {
       target = target.prototype;
       key = typeof config === 'string' ? config : config.name;
     }
@@ -5274,6 +5276,10 @@ function observable(targetOrConfig, key, descriptor) {
       descriptor = {};
     }
 
+    if (!('enumerable' in descriptor)) {
+      descriptor.enumerable = true;
+    }
+
     delete descriptor.writable;
     delete descriptor.initializer;
 
@@ -5290,7 +5296,11 @@ function observable(targetOrConfig, key, descriptor) {
 
     descriptor.get.dependencies = [innerPropertyName];
 
-    Reflect.defineProperty(target, key, descriptor);
+    if (isClassDecorator) {
+      Reflect.defineProperty(target, key, descriptor);
+    } else {
+      return descriptor;
+    }
   }
 
   if (key === undefined) {
diff --git a/dist/es2015/aurelia-binding.js b/dist/es2015/aurelia-binding.js
index da629c38..8a827da3 100644
--- a/dist/es2015/aurelia-binding.js
+++ b/dist/es2015/aurelia-binding.js
@@ -1675,21 +1675,12 @@ export let LiteralObject = class LiteralObject extends Expression {
   }
 };
 
-let evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
 function evalList(scope, list, lookupFunctions) {
-  let length = list.length;
-
-  for (let cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-    evalListCache.push([]);
-  }
-
-  let result = evalListCache[length];
-
-  for (let i = 0; i < length; ++i) {
+  const length = list.length;
+  const result = [];
+  for (let i = 0; i < length; i++) {
     result[i] = list[i].evaluate(scope, lookupFunctions);
   }
-
   return result;
 }
 
@@ -2744,7 +2735,7 @@ export let ParserImplementation = class ParserImplementation {
       if (this.optional('.')) {
         name = this.peek.key;
         this.advance();
-      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}' || this.peek.text === ',') {
         return new AccessThis(ancestor);
       } else {
         this.error(`Unexpected token ${ this.peek.text }`);
@@ -3352,6 +3343,16 @@ export let StyleObserver = class StyleObserver {
     return this.element.style.cssText;
   }
 
+  _setProperty(style, value) {
+    let priority = '';
+
+    if (value.indexOf('!important') !== -1) {
+      priority = 'important';
+      value = value.replace('!important', '');
+    }
+    this.element.style.setProperty(style, value, priority);
+  }
+
   setValue(newValue) {
     let styles = this.styles || {};
     let style;
@@ -3362,7 +3363,7 @@ export let StyleObserver = class StyleObserver {
         for (style in newValue) {
           if (newValue.hasOwnProperty(style)) {
             styles[style] = version;
-            this.element.style[style] = newValue[style];
+            this._setProperty(style, newValue[style]);
           }
         }
       } else if (newValue.length) {
@@ -3375,7 +3376,7 @@ export let StyleObserver = class StyleObserver {
           }
 
           styles[style] = version;
-          this.element.style[style] = pair[2];
+          this._setProperty(style, pair[2]);
         }
       }
     }
@@ -3393,7 +3394,7 @@ export let StyleObserver = class StyleObserver {
         continue;
       }
 
-      this.element.style[style] = '';
+      this.element.style.removeProperty(style);
     }
   }
 
@@ -4176,7 +4177,7 @@ export let ObserverLocator = (_temp = _class11 = class ObserverLocator {
       if (xlinkResult) {
         return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
       }
-      if (/^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
+      if (propertyName === 'role' && (obj instanceof DOM.Element || obj instanceof DOM.SVGElement) || /^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
         return new DataAttributeObserver(obj, propertyName);
       }
     }
@@ -4798,7 +4799,8 @@ let ModifySetObserver = class ModifySetObserver extends ModifyCollectionObserver
 
 export function observable(targetOrConfig, key, descriptor) {
   function deco(target, key, descriptor, config) {
-    if (key === undefined) {
+    const isClassDecorator = key === undefined;
+    if (isClassDecorator) {
       target = target.prototype;
       key = typeof config === 'string' ? config : config.name;
     }
@@ -4815,6 +4817,10 @@ export function observable(targetOrConfig, key, descriptor) {
       descriptor = {};
     }
 
+    if (!('enumerable' in descriptor)) {
+      descriptor.enumerable = true;
+    }
+
     delete descriptor.writable;
     delete descriptor.initializer;
 
@@ -4831,7 +4837,11 @@ export function observable(targetOrConfig, key, descriptor) {
 
     descriptor.get.dependencies = [innerPropertyName];
 
-    Reflect.defineProperty(target, key, descriptor);
+    if (isClassDecorator) {
+      Reflect.defineProperty(target, key, descriptor);
+    } else {
+      return descriptor;
+    }
   }
 
   if (key === undefined) {
diff --git a/dist/native-modules/aurelia-binding.js b/dist/native-modules/aurelia-binding.js
index a13984f3..f435e639 100644
--- a/dist/native-modules/aurelia-binding.js
+++ b/dist/native-modules/aurelia-binding.js
@@ -1841,21 +1841,12 @@ export var LiteralObject = function (_Expression18) {
   return LiteralObject;
 }(Expression);
 
-var evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
 function evalList(scope, list, lookupFunctions) {
   var length = list.length;
-
-  for (var cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-    evalListCache.push([]);
-  }
-
-  var result = evalListCache[length];
-
-  for (var _i14 = 0; _i14 < length; ++_i14) {
+  var result = [];
+  for (var _i14 = 0; _i14 < length; _i14++) {
     result[_i14] = list[_i14].evaluate(scope, lookupFunctions);
   }
-
   return result;
 }
 
@@ -2938,7 +2929,7 @@ export var ParserImplementation = function () {
       if (this.optional('.')) {
         name = this.peek.key;
         this.advance();
-      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+      } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}' || this.peek.text === ',') {
         return new AccessThis(ancestor);
       } else {
         this.error('Unexpected token ' + this.peek.text);
@@ -3616,6 +3607,16 @@ export var StyleObserver = function () {
     return this.element.style.cssText;
   };
 
+  StyleObserver.prototype._setProperty = function _setProperty(style, value) {
+    var priority = '';
+
+    if (value.indexOf('!important') !== -1) {
+      priority = 'important';
+      value = value.replace('!important', '');
+    }
+    this.element.style.setProperty(style, value, priority);
+  };
+
   StyleObserver.prototype.setValue = function setValue(newValue) {
     var styles = this.styles || {};
     var style = void 0;
@@ -3626,7 +3627,7 @@ export var StyleObserver = function () {
         for (style in newValue) {
           if (newValue.hasOwnProperty(style)) {
             styles[style] = version;
-            this.element.style[style] = newValue[style];
+            this._setProperty(style, newValue[style]);
           }
         }
       } else if (newValue.length) {
@@ -3639,7 +3640,7 @@ export var StyleObserver = function () {
           }
 
           styles[style] = version;
-          this.element.style[style] = pair[2];
+          this._setProperty(style, pair[2]);
         }
       }
     }
@@ -3657,7 +3658,7 @@ export var StyleObserver = function () {
         continue;
       }
 
-      this.element.style[style] = '';
+      this.element.style.removeProperty(style);
     }
   };
 
@@ -4519,7 +4520,7 @@ export var ObserverLocator = (_temp = _class11 = function () {
       if (xlinkResult) {
         return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
       }
-      if (/^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
+      if (propertyName === 'role' && (obj instanceof DOM.Element || obj instanceof DOM.SVGElement) || /^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
         return new DataAttributeObserver(obj, propertyName);
       }
     }
@@ -5219,7 +5220,8 @@ var ModifySetObserver = function (_ModifyCollectionObse3) {
 
 export function observable(targetOrConfig, key, descriptor) {
   function deco(target, key, descriptor, config) {
-    if (key === undefined) {
+    var isClassDecorator = key === undefined;
+    if (isClassDecorator) {
       target = target.prototype;
       key = typeof config === 'string' ? config : config.name;
     }
@@ -5236,6 +5238,10 @@ export function observable(targetOrConfig, key, descriptor) {
       descriptor = {};
     }
 
+    if (!('enumerable' in descriptor)) {
+      descriptor.enumerable = true;
+    }
+
     delete descriptor.writable;
     delete descriptor.initializer;
 
@@ -5252,7 +5258,11 @@ export function observable(targetOrConfig, key, descriptor) {
 
     descriptor.get.dependencies = [innerPropertyName];
 
-    Reflect.defineProperty(target, key, descriptor);
+    if (isClassDecorator) {
+      Reflect.defineProperty(target, key, descriptor);
+    } else {
+      return descriptor;
+    }
   }
 
   if (key === undefined) {
diff --git a/dist/system/aurelia-binding.js b/dist/system/aurelia-binding.js
index e92135bb..20060ebc 100644
--- a/dist/system/aurelia-binding.js
+++ b/dist/system/aurelia-binding.js
@@ -3,7 +3,7 @@
 System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aurelia-metadata'], function (_export, _context) {
   "use strict";
 
-  var LogManager, PLATFORM, DOM, TaskQueue, metadata, _typeof, _createClass, _dec, _dec2, _class, _dec3, _class2, _dec4, _class3, _dec5, _class5, _dec6, _class7, _dec7, _class8, _dec8, _class9, _dec9, _class10, _class11, _temp, _dec10, _class12, _class13, _temp2, map, sourceContext, slotNames, versionSlotNames, i, bindings, minimumImmediate, frameBudget, isFlushRequested, immediate, arrayPool1, arrayPool2, poolUtilization, ExpressionObserver, EDIT_LEAVE, EDIT_UPDATE, EDIT_ADD, EDIT_DELETE, arraySplice, ModifyCollectionObserver, CollectionLengthObserver, pop, push, reverse, shift, sort, splice, unshift, ModifyArrayObserver, Expression, Chain, BindingBehavior, ValueConverter, Assign, Conditional, AccessThis, AccessScope, AccessMember, AccessKeyed, CallScope, CallMember, CallFunction, Binary, PrefixNot, LiteralPrimitive, LiteralString, LiteralArray, LiteralObject, evalListCache, Unparser, ExpressionCloner, bindingMode, Token, Lexer, Scanner, OPERATORS, $EOF, $TAB, $LF, $VTAB, $FF, $CR, $SPACE, $BANG, $DQ, $$, $PERCENT, $AMPERSAND, $SQ, $LPAREN, $RPAREN, $STAR, $PLUS, $COMMA, $MINUS, $PERIOD, $SLASH, $COLON, $SEMICOLON, $LT, $EQ, $GT, $QUESTION, $0, $9, $A, $E, $Z, $LBRACKET, $BACKSLASH, $RBRACKET, $CARET, $_, $a, $e, $f, $n, $r, $t, $u, $v, $z, $LBRACE, $BAR, $RBRACE, $NBSP, EOF, Parser, ParserImplementation, mapProto, ModifyMapObserver, DelegateHandlerEntry, DefaultEventStrategy, EventManager, DirtyChecker, DirtyCheckProperty, logger, propertyAccessor, PrimitiveObserver, SetterObserver, XLinkAttributeObserver, dataAttributeAccessor, DataAttributeObserver, StyleObserver, ValueAttributeObserver, checkedArrayContext, checkedValueContext, CheckedObserver, selectArrayContext, SelectValueObserver, ClassObserver, ComputedExpression, elements, presentationElements, presentationAttributes, SVGAnalyzer, ObserverLocator, ObjectObservationAdapter, BindingExpression, targetContext, Binding, CallExpression, Call, ValueConverterResource, BindingBehaviorResource, ListenerExpression, Listener, NameExpression, NameBinder, LookupFunctions, BindingEngine, setProto, ModifySetObserver;
+  var LogManager, PLATFORM, DOM, TaskQueue, metadata, _typeof, _createClass, _dec, _dec2, _class, _dec3, _class2, _dec4, _class3, _dec5, _class5, _dec6, _class7, _dec7, _class8, _dec8, _class9, _dec9, _class10, _class11, _temp, _dec10, _class12, _class13, _temp2, map, sourceContext, slotNames, versionSlotNames, i, bindings, minimumImmediate, frameBudget, isFlushRequested, immediate, arrayPool1, arrayPool2, poolUtilization, ExpressionObserver, EDIT_LEAVE, EDIT_UPDATE, EDIT_ADD, EDIT_DELETE, arraySplice, ModifyCollectionObserver, CollectionLengthObserver, pop, push, reverse, shift, sort, splice, unshift, ModifyArrayObserver, Expression, Chain, BindingBehavior, ValueConverter, Assign, Conditional, AccessThis, AccessScope, AccessMember, AccessKeyed, CallScope, CallMember, CallFunction, Binary, PrefixNot, LiteralPrimitive, LiteralString, LiteralArray, LiteralObject, Unparser, ExpressionCloner, bindingMode, Token, Lexer, Scanner, OPERATORS, $EOF, $TAB, $LF, $VTAB, $FF, $CR, $SPACE, $BANG, $DQ, $$, $PERCENT, $AMPERSAND, $SQ, $LPAREN, $RPAREN, $STAR, $PLUS, $COMMA, $MINUS, $PERIOD, $SLASH, $COLON, $SEMICOLON, $LT, $EQ, $GT, $QUESTION, $0, $9, $A, $E, $Z, $LBRACKET, $BACKSLASH, $RBRACKET, $CARET, $_, $a, $e, $f, $n, $r, $t, $u, $v, $z, $LBRACE, $BAR, $RBRACE, $NBSP, EOF, Parser, ParserImplementation, mapProto, ModifyMapObserver, DelegateHandlerEntry, DefaultEventStrategy, EventManager, DirtyChecker, DirtyCheckProperty, logger, propertyAccessor, PrimitiveObserver, SetterObserver, XLinkAttributeObserver, dataAttributeAccessor, DataAttributeObserver, StyleObserver, ValueAttributeObserver, checkedArrayContext, checkedValueContext, CheckedObserver, selectArrayContext, SelectValueObserver, ClassObserver, ComputedExpression, elements, presentationElements, presentationAttributes, SVGAnalyzer, ObserverLocator, ObjectObservationAdapter, BindingExpression, targetContext, Binding, CallExpression, Call, ValueConverterResource, BindingBehaviorResource, ListenerExpression, Listener, NameExpression, NameBinder, LookupFunctions, BindingEngine, setProto, ModifySetObserver;
 
   function _possibleConstructorReturn(self, call) {
     if (!self) {
@@ -559,17 +559,10 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
 
   function evalList(scope, list, lookupFunctions) {
     var length = list.length;
-
-    for (var cacheLength = evalListCache.length; cacheLength <= length; ++cacheLength) {
-      evalListCache.push([]);
-    }
-
-    var result = evalListCache[length];
-
-    for (var _i14 = 0; _i14 < length; ++_i14) {
+    var result = [];
+    for (var _i14 = 0; _i14 < length; _i14++) {
       result[_i14] = list[_i14].evaluate(scope, lookupFunctions);
     }
-
     return result;
   }
 
@@ -815,7 +808,8 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
 
   function observable(targetOrConfig, key, descriptor) {
     function deco(target, key, descriptor, config) {
-      if (key === undefined) {
+      var isClassDecorator = key === undefined;
+      if (isClassDecorator) {
         target = target.prototype;
         key = typeof config === 'string' ? config : config.name;
       }
@@ -832,6 +826,10 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
         descriptor = {};
       }
 
+      if (!('enumerable' in descriptor)) {
+        descriptor.enumerable = true;
+      }
+
       delete descriptor.writable;
       delete descriptor.initializer;
 
@@ -848,7 +846,11 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
 
       descriptor.get.dependencies = [innerPropertyName];
 
-      Reflect.defineProperty(target, key, descriptor);
+      if (isClassDecorator) {
+        Reflect.defineProperty(target, key, descriptor);
+      } else {
+        return descriptor;
+      }
     }
 
     if (key === undefined) {
@@ -2261,8 +2263,6 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
 
       _export('LiteralObject', LiteralObject);
 
-      evalListCache = [[], [0], [0, 0], [0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0, 0]];
-
       _export('Unparser', Unparser = function () {
         function Unparser(buffer) {
           
@@ -3234,7 +3234,7 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
             if (this.optional('.')) {
               name = this.peek.key;
               this.advance();
-            } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}') {
+            } else if (this.peek === EOF || this.peek.text === '(' || this.peek.text === '[' || this.peek.text === '}' || this.peek.text === ',') {
               return new AccessThis(ancestor);
             } else {
               this.error('Unexpected token ' + this.peek.text);
@@ -3897,6 +3897,16 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
           return this.element.style.cssText;
         };
 
+        StyleObserver.prototype._setProperty = function _setProperty(style, value) {
+          var priority = '';
+
+          if (value.indexOf('!important') !== -1) {
+            priority = 'important';
+            value = value.replace('!important', '');
+          }
+          this.element.style.setProperty(style, value, priority);
+        };
+
         StyleObserver.prototype.setValue = function setValue(newValue) {
           var styles = this.styles || {};
           var style = void 0;
@@ -3907,7 +3917,7 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
               for (style in newValue) {
                 if (newValue.hasOwnProperty(style)) {
                   styles[style] = version;
-                  this.element.style[style] = newValue[style];
+                  this._setProperty(style, newValue[style]);
                 }
               }
             } else if (newValue.length) {
@@ -3920,7 +3930,7 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
                 }
 
                 styles[style] = version;
-                this.element.style[style] = pair[2];
+                this._setProperty(style, pair[2]);
               }
             }
           }
@@ -3938,7 +3948,7 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
               continue;
             }
 
-            this.element.style[style] = '';
+            this.element.style.removeProperty(style);
           }
         };
 
@@ -4779,7 +4789,7 @@ System.register(['aurelia-logging', 'aurelia-pal', 'aurelia-task-queue', 'aureli
             if (xlinkResult) {
               return new XLinkAttributeObserver(obj, propertyName, xlinkResult[1]);
             }
-            if (/^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
+            if (propertyName === 'role' && (obj instanceof DOM.Element || obj instanceof DOM.SVGElement) || /^\w+:|^data-|^aria-/.test(propertyName) || obj instanceof DOM.SVGElement && this.svgAnalyzer.isStandardSvgAttribute(obj.nodeName, propertyName)) {
               return new DataAttributeObserver(obj, propertyName);
             }
           }
diff --git a/doc/CHANGELOG.md b/doc/CHANGELOG.md
index e3dd4da1..b5aaf636 100644
--- a/doc/CHANGELOG.md
+++ b/doc/CHANGELOG.md
@@ -1,3 +1,17 @@
+<a name="1.0.5"></a>
+## [1.0.5](https://github.com/aurelia/binding/compare/1.0.4...v1.0.5) (2016-09-29)
+
+
+### Bug Fixes
+
+* **AST:** remove evalList array cache ([73f1a3e](https://github.com/aurelia/binding/commit/73f1a3e)), closes [#495](https://github.com/aurelia/binding/issues/495)
+* **observable:** enable chaining, enumerating ([6586cd2](https://github.com/aurelia/binding/commit/6586cd2)), closes [#501](https://github.com/aurelia/binding/issues/501)
+* **ObserverLocator:** use correct observer for aria role ([ca1dd60](https://github.com/aurelia/binding/commit/ca1dd60)), closes [aurelia/framework#582](https://github.com/aurelia/framework/issues/582) [#486](https://github.com/aurelia/binding/issues/486)
+* **Parser:** fix object literal parsing with ([52d01dd](https://github.com/aurelia/binding/commit/52d01dd)), closes [#502](https://github.com/aurelia/binding/issues/502)
+* **StyleObserver:** enable !important override ([0872d12](https://github.com/aurelia/binding/commit/0872d12)), closes [aurelia/templating-resources#251](https://github.com/aurelia/templating-resources/issues/251)
+
+
+
 <a name="1.0.4"></a>
 ## [1.0.4](https://github.com/aurelia/binding/compare/1.0.3...v1.0.4) (2016-09-07)
 
diff --git a/package.json b/package.json
index 9b7de291..43556f2d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "aurelia-binding",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "description": "A modern databinding library for JavaScript and HTML.",
   "keywords": [
     "aurelia",