Catalyst 64-bit Beta 4 for me here, since I use Windows XP Professional x64 Edition (RC2).
I might add that, considering it's a beta driver, it does the job extremely well! All games play extremely smoothly on my ATI Radeon X800 XT PE. The only thing that somewhat bothers me, though, is that the video files have some artifacts/glitches during playback in any player. There is probably a workaround, though, but I haven't tried messing around with it yet.