Why Windows XP?
GSUK: What will Windows XP offer gamers?
Mark Croft: I think the key things here are you get your in-built DirectX 8.1. Okay, you could put that on Win 98 or Millennium, but on a technical level, XP is running in a kernel mode driver. So, if you like its amazing implementation, when we get everything lined up with the graphics cards, that should give us really good performance. There will be more stability. We do more work with error checking with graphics handling in Windows XP, than we've done in any version of Win 9x. [As for] the high end graphics card manufacturers - [they're focused on] people who are buying PCs now, and what gamers are using now. Does XP add any new features? No.
Well jeeze.. it's better than Win9x for stability (No mention of Win2K) and doesnt add any new features. Even a MS guy trying to pitch the OS doesnt seem to offer any compelling reasons to switch for gamers. (I've been running Win2K for a long while now btw.. highly recommended). Also, NTCompatible has put together a WindowsXP FAQ worth reading.