Ember.ObjectController and Ember.ArrayController have been deprecated for a while and will be gone in ember 2.0, but for autogenerated controllers will still be of those types for backwards compatibility.
This addon reexports Ember.Controller as App.ObjectController and App.ArrayController, so you can stop using them right now and make your migration to the future Ember 2.0 easier.
ember install ember-disable-proxy-controllers