... I'm pretty sure typical MVC uses some form of event as well, i.e. an event is created to inform the view that the model has changed. (Even the wikipedia page differentiates passive MVC implementations where the language/platform cannot implement events.)
Somehow, I'm just seeing the Observer pattern and the MVC pattern in the OPs post.
My thoughts exactly. Extend your main app var with Backbone.Events and u have a global event system.