The closest thing I've seen is this: http://blog.stevensanderson.com/2012/08/01/rich-javascript-a...

Doesn't give adoption rate, but it does give an idea of relative popularity as of last august.

That's a great article (I'd read it before). I would love to see someone come with a fancy way of scanning github, twitter, etc. to find numbers to gauge the interest in each of these frameworks/libraries.

Based on our experience working with clients at Cantina, Backbone seems to have the biggest mindshare and widest adoption. We have several active projects that are making use of it.

There has been some passing interest in Angular and Ember, but nothing concrete yet. The press on Ember for the past few months may raise more awareness.