This is a minor release of Backbone Fundamentals, but comes with a relatively large backlog of changes. These have been available live on the book site for some time, but are finally getting tagged to get back onto a more regular release cycle.
Changes are up on the site already: http://addyosmani.github.io/backbone-fundamentals/
We've also bumped checked in versions of ePub, Markdown & Mobi versions of the book. We'll try to get out a revised PDF version shortly.