As mentioned in a couple places, though we need to communicate it more, metal-views is not HTMLBars. metal-views had the goals of:
- Refactoring the view layer to remove recursion
- Replacing the metamorph library (script tags) with the morph library (text nodes)
In general, metal-views prepared the Ember codebase for HTMLBars. Many helpers need to be re-written for HTMLBars to be merged, but most/all of the view layer refactoring is complete.
Ember.js follows semantic versioning, so all your existing Handlebars templates will continue to work in HTMLBars. They will just be faster! The usage for you as an application developer remains the same, with the option of using a few new HTMLBars only syntaxes such as avoiding bind-attr: <div class="{{someClass}}"></div>.
Metal views is slated to ship in Ember 1.8, and HTMLBars is likely close behind.