Getting started with Ember is a lot harder than your comment admits. I tried Ember recently and there was still a lot of stuff that was broken including the data model. That would make building a non-trivial app hard.
Ember applications start out with a complexity rating of 4/10 but never get much higher than 6/10, regardless of how sophisticated your application becomes. Backbone starts out at 1/10 but complexity grows linearly. This is a natural side effect of the types of applications the two frameworks were specifically created for.
https://github.com/emberjs/ember.js/wiki/Production-Deployme...
Shopitome is a very fresh deployment using emberjs based on this tweet sent today:
http://twitter.com/inkredabull/status/268017623428657153
http://www.shopittome.com/threads/signup
A few non trivial companies using emberjs in production are:
www.zendesk.com