This is what I was talking about. Same thing could go for the routes as well.

file.js

App.ModelIndexController = Ember.ObjectController.extend({
  //stuff
});

App.ModelNewController = Ember.ObjectController.extend({
  //stuff
});

App.ModelController = Ember.ObjectController.extend({
  index: function(){
    //stuff
  },
  new: function(){
    //stuff
  }
});

// this second time we call Ember.ObjectController.extend once, code is better organized looking and less of a clutter.