I keep on hearing this, but I really haven't heard of it being in any large projects other than DoubleClick. I don't know if I'd consider being used in a bunch of small hobby projects a 'head start'.
Not saying that represents the market, but just saying it's taken off in my corner of the world significantly.
Youtube App for PS3
there is a lot more, it's being used in a lot of startups and major companies throughout the world today, pretty sure the stats show it is far ahead of ember in real world adoption so far
Square, Vine, Yahoo, NBC News, Groupon, Twitch, Urbanspoon, Discourse, Ghost, TravisCI, and now Netflix?
Databinding is a lock-in feature. Annoying as hell, but true. There's no databinding library that I've seen that does not reduce your ability to use other libraries. I've never seen one that jives at ALL with third-party client templates (like dustjs).
There are definitely two questions worth asking:
1) Is that combination really what we want? (I think it is)
and
2) Is Angular's approach the only right way to do it?
So far, they've got the mindshare and a serious head start.