diff --git a/lib/es.js b/lib/es.js
index f7b02060..4820f36d 100644
--- a/lib/es.js
+++ b/lib/es.js
@@ -34,17 +34,13 @@
       var loader = this;
       return translate.call(loader, load)
       .then(function(source) {
-        if (load.metadata.format === 'es6')
-          throw new TypeError(load.name + ' has been configured to use the "es6" module format, which has been renamed to "es".'
-              + '\n\tSet `System.meta["' + load.name + '"] = {format: "es"}` to resolve this.');
-        
         // detect & transpile ES6
-        if (load.metadata.format == 'es' || !load.metadata.format && source.match(esRegEx)) {
+        if (load.metadata.format == 'es' || load.metadata.format == 'es6' || !load.metadata.format && source.match(esRegEx)) {
           load.metadata.format = 'es';          
           return transpile.call(loader, load);
         }
 
-        if (load.metadata.format == 'system') {
+        if (load.metadata.format == 'system' || load.metadata.format == 'register') {
           if (!__global.$traceurRuntime && load.source.match(traceurRuntimeRegEx)) {
             return loader['import']('traceur-runtime').then(function() {
               return source;
diff --git a/lib/meta.js b/lib/meta.js
index 234e6558..9ef7b72e 100644
--- a/lib/meta.js
+++ b/lib/meta.js
@@ -117,7 +117,18 @@
           if (metaName) {
             var metaValue = metaString.substr(metaName.length + 1, metaString.length - metaName.length - 1);
 
-            setMetaProperty(load.metadata, metaName, metaValue);
+            // support "deps [jquery,bootstrap]" array syntax
+            if (metaValue[0] == '[' && metaValue[metaValue.length - 1] == ']')
+              metaValue = metaValue.substr(1, metaValue.length - 2).split(',');
+
+            // Array addition backwards-compatibility, to be deprecated
+            if (load.metadata[metaName] instanceof Array) {
+              if (!(metaValue instanceof Array))
+                metaValue = [metaValue];
+              load.metadata[metaName] = load.metadata[metaName].concat(metaValue);
+            }
+            else
+              setMetaProperty(load.metadata, metaName, metaValue);
           }
         }
       }
diff --git a/lib/register.js b/lib/register.js
index ddd34255..62171250 100644
--- a/lib/register.js
+++ b/lib/register.js
@@ -56,7 +56,7 @@
     // dynamic backwards-compatibility
     // can be deprecated eventually
     if (typeof declare == 'boolean')
-      throw new TypeError('System.register has been split into System.register and System.registerDyanmic taking three arguments and four argument forms respectively. The bundle may need to be rebuilt.');
+      return this.registerDynamic.apply(this, arguments);
 
     doRegister(this, name, {
       declarative: true,
@@ -426,7 +426,7 @@
       anonRegister = null;
       calledRegister = false;
       
-      if (load.metadata.format == 'system')
+      if (load.metadata.format == 'system' || load.metadata.format == 'register')
         load.metadata.scriptLoad = true;
       
       return fetch.call(this, load);
@@ -443,7 +443,7 @@
         load.metadata.deps = load.metadata.deps || [];
 
         // run detection for register format
-        if (load.metadata.format == 'system' || !load.metadata.format && load.source.match(registerRegEx))
+        if (load.metadata.format == 'system' || load.metadata.format == 'register' || !load.metadata.format && load.source.match(registerRegEx))
           load.metadata.format = 'system';
         return source;
       });
@@ -456,9 +456,6 @@
 
       var entry;
 
-      if (load.metadata.format == 'register')
-        throw new TypeError(load.name + ' defined as format "register", which has been renamed to "system".');
-
       // first we check if this module has already been defined in the registry
       if (loader.defined[load.name]) {
         entry = loader.defined[load.name];
@@ -480,7 +477,7 @@
       }
 
       // Contains System.register calls
-      else if (load.metadata.format == 'system' || load.metadata.format == 'es') {
+      else if (load.metadata.format == 'system' || load.metadata.format == 'register' || load.metadata.format == 'es' || load.metadata.format == 'es6') {
         anonRegister = null;
         calledRegister = false;