I really wish there was some thorough examples of using Ember + Ember-Data. Ideally it would be backend agnostic (mocked client side xmlhttprequest) and go from doing simple things like saving a model all the way to doing more complex things like you showed.
Drupal for instance has a /really/ great project that maintains a bunch of thorough examples (https://drupal.org/project/examples) which were indispensable when I did Drupal a while back.