@darkbaby123 metal-views has several goals, which in combination prepare Ember for HTMLBars. Among them are to remove recursion from the rendering pipeline and use the morph library instead of metamorph. It is very likely that this branch will make it into the 1.8 beta that branches this weekend.
@racamp101 @johnny_bushy There are a few things that will have better support in HTMLBars than they do in Handlebars, for example SVG components, but for the most part this is a change that maintains complete feature parity. You can write your apps in Ember today and the upgrade will be transparent, except for the suddenly faster rendering time. Don’t wait!