This app shows 2 ways to "sprinkle" Ember into your Rails app. It's in support of an Austin on Rails talk given in Feb. 2014. Slides are here: https://speakerdeck.com/tehviking/a-sprinkling-of-ember
The first technique is embedding Ember components into an existing app rather than a jQuery hairball.
You can see more details in a blog post here: http://frontside.io/blog/2014/03/06/a-sprinkling-of-ember.html
The second technique is actually mounting an Ember routed application at a sub-route of your Rails app.
There's no blog post for this yet, but expect one in the near future.