I purchased Developing an Ember.js Edge a couple of days ago. I have not finished the book yet, but just starting working through the sample application.
The book is out of date, and the example application hasn’t been updated in 9 months, but I still think there are some things you can take away from the book to help you improve as an ember.js developer.
Here is a review of the book from back in January.
I’m probably going to re-write their sample ticket tracking app using ember-cli. I’ll keep you updated on my progress.