To be honest, I'm a bit more impressed by the flash-like capabilities of raphael.js rather than the icon set itself. It's great stuff. http://raphaeljs.com/
Last time I checked it out, it was intolerably slow on a low-end machine. Now, on that same machine but with the latest Chrome beta, the performance is perfectly tolerable. Looks like gRaphaël is going to be something I might want to use someday after all, so thanks for making me look again.
FWIW, I just tried some of their demos on the iPad and.. feels pretty normal. I know the iPad isn't the slowest of the slow but it's JavaScript engine is miles behind even the slowest ones on desktop machines.