The text is appreciated, but too long. More importantly, there are no demos. That text is valuable but should be broken up into smaller sectional chunks, each associated with code and functional demos

Looks interesting but I can't figure out why there's no hosted demo. Hard to be inspired to think of a use case or want to play with it when I can't see a demo without pulling the code.

I've been wanting something like this, thanks! It can be tedious to set up animations by hand in the CSS, and since animations have more to do with behavior than styling, it makes the code a lot cleaner.

A nice-to-have would be detecting the presence of common JS libraries, and falling back to jQuery/etc DOM-based animation on browsers that do not support CSS transitions.

Other than the recently proposed 3D transforms, what's incomplete about Firefox's 4 implementation?