I downloaded Google's new browser, Chrome, and you can really tell it's a beta. It's stable as heck, but pages are very slow to load, and some never seem to load at all. Ironically, it's Google's own pages (gmail most particularly) that most often have this problem.
I'm looking forward to the next version, but sticking with Firefox for now.
Update: It's much, much better in Vista, and the transition from Firefox was seamless.