"There are 30 million PS2 owners and guess what? Those are the same 30 million AOL users" ... yeah, and I bet you're one of the same people that were behind Nintendo when they started screaming "Quality over quantity". Honestly, I've got a PS2 and an XBox ... let's just say that the PS2 and PC take priority.
As for HALO on the PC, the game is not "all that"; I mean the AI is sweet and the environments are lush, but with Unreal 2, Doom 3, and possibly Duke Nukem (OK, maybe not) Halo will end up being a second rate FPS by those standards.