Also no problems installing 3 beta here -- one thing I do really like is the new Find feature, which works like FireFox's. A "find" bar appears at the top of the window, and it highlights all the occurrences on a page as you type. And, it shows a quick but useful orange hilite animation as you cycle through the found bits so you can actually see what's being found (before, the page would jump somewhere when you hit Cmd-G and the hilites were often impossible to see).

I do notice a bit more fan revving, but it's beta, after all. All in all a nice (if small) improvement to the mac version. I also tried the Windows version and it's a little rougher around the edges; it's kind of dark and gloomy looking, with a noticeably darker grey, and fonts seem a bit too soft. But that's a great first step, and a smart move.