As Paul mentioned, all the backbone objects, including the Router, have the Event object extended, so you can set up event listeners on these. But I understand why you want to centralize the management of the events, so that you don't need to set up event listeners on various objects, or pass in an event aggregator.
Derick Bailey talks about this in the post below, and the solution he proposes is to create an App level event aggreagator.
http://lostechies.com/derickbailey/2012/04/03/revisiting-the-backbone-event-aggregator-lessons-learned/
Also, if you are doing anything more complex than the "to-do" application, I would encourage you to look at some of the Backbone frameworks, like Chaplin, Marionette, boilerplate etc. You can find the list here
In my application, I'm using the Marionette framework, and have found it really useful in creating modularized, easy to maintain code, with a lot of the usual repititive code already handled within it.