I'm also kind of sick of seeing stuff done with canvases that could probably be done as efficiently or more efficiently without. (It would be particularly cool for someone to implement a library that abstracted out the back-end, so you could run in DHTML4 or excanvas or a real canvas.)
I've seriously thought about surgically removing Closure from limejs. It uses a lot of Closure classes (i.e. Vector2) so it wouldn't be clean, but improving the build process would be worth it.
