Oh, wow! This is awesome; I'm just now at the point in a Backbone project where I was preparing to implement something similar, and wasn't exactly relishing the thought. It's awesome that I now have something to work with instead of having to roll my own.

I do have one suggestion, though: while it's of course not much work to compile the script to JavaScript, it couldn't hurt to include a current JS version in the repo for people who don't have Node & CoffeeScript installed.