Ok, WoW sucks on Vista64. I'm sure I have a few settings tweaked in XP (such as running windowed mode maximized instead of full screen), but the frame rate in Vista64 was less than half of the frame rate in XP. I logged into my 15 blood elf and walked around near the bank in Silvermoon City. In XP, I was getting 50-60fps. In Vista64, I was getting 18-23fps. Thinking I had a bunch of stuff turned down, I went into graphic options and turned everything I can up to maximum (except anti aliasing, which I never played with in the first place). I was still getting about 50fps in XP compared to 20fps in Vista64.