“Microsoft's next-generation Xbox will ditch its Intel chip in favor of the same kind of chip used in Apple's Macs -- an IBM PowerPC processor -- IBM and Microsoft announced on Monday.
Doherty said IBM chips will now power all the major game consoles -- the next-generation PlayStation will be based on IBM's The Cell, and Nintendo currently uses the PowerPC in the GameCube.
Microsoft will use the Virtual PC technology it acquired from Connectix last year to provide backward-compatibility with the current generation of Xbox games. “ 
 XBox to Switch to PowerPC. Wired. http://www.wired.com/news/games/0,2101,61065,00.html?tw=wn_tophead_1