You can install Windows XP on your PS3 no problem. There are forums out there with instructions on how to do it.
I have never tried to run WoW or anything like that but providing the game / application you are running will accept the video chip on the PS3 then logically it should work.
I have a second drive I installe windows XP on for my PS3 but honestly I never tried installing games as getting Windows XP to boot was an accomplishment in itself.
Thought I should edit and explain, they are using a version of linux like Fedora and using Qemu emulator to run Windows XP. I hav yet to hear of a direct install of Windows XP because the architecture of the PS3 isn't like x86 it's more in comparison to PPC.
Edited, Feb 13th 2008 6:31am by xXBijiontXx