At my place of work (large, slow) Ember is starting to get widely used. "Google uses/supports it" is instant justification for using it to any layer of management, and I think that's the source of its success. (At least where I'm working people are afraid of using Ember because it's harder to explain/justify to the suits.)

Likewise, I expect at some point we'll be using node.js (probably over Rails/Django) because it's a lot more obvious to 'management' that it's used by large organizations.