Here (Celeron 550, XP SP3, Chrome 5.0.375.125 beta) Chrome is on 100%, too. No problems with clipping though. Firefox 3.6.8 (on the same machine) was too slow for the real experience.
JS is a new Flash? Joking aside, it's impressive what you can do in 1k JS. And, let's hope all browsers will start to utilize the GPU as MS has demonstrated in the IE9 preview.