We've tackled auth in our app at Batterii. Our solution was unconventional and has been replaced by alternate options in Ember native.
I think the most modern solution for handling this I've seen is making an `Authenticated` route class that takes advantage of Ember.Route's `beforeModel` to conditionally. There is a good example in this gist:
https://gist.github.com/machty/5647589 (see: "authenticated route"). The premise is that any route that requires a user to be logged in would extend your `Authenticated` route and automatically check credentials.
I'm happy to see more folks getting into Ember. If you have any questions or even want to pair for a day to get up to speed on stuff, I'm more than happy to help.