In Ember 0.9, calling set during init will

1. set the property
2. notify all observers and dependent properties

In Ember 1, it only does the first. That is, objects are in a "silent" mode during init.

Ember 1 provides an .on('init') hook that runs just after init finishes. It is the recommended way of providing additional initialization behavior.

If you have code that looks like

var MyObject = Ember.Object.extend({
  
  init: function() {
    var result = this._super();
    this.set('someArray', []);
  }

});

and you expect any dependencies of someArray to be notified, you should change it to

var MyObject = Ember.Object.extend({
  
  initializeSomeArray: function() {
    this.set('someArray', []);
  }.on('init')

});