Problems with temporary records created to back forms

Example: http://ift.tt/1BC0OeY

1. A new un-saved record created to back the New Todo form, shows up in the Todos listing.

2. Such records also fire computed property observers. To workaround such scenarios, almost all usages of computed properties would need to observe non 'isNew' or 'saved' instances of items in the collection.

Is there a way to create detached records to back such forms and later push it into the store?

While this is a trivial example, wouldn't a Ember-data model's associations only need to work in the context of non 'isNew' records.