Microsoft and IBM announced today that IBM technology will power "future Xbox products and services". Details are scarce, but according to the press release, "the new Xbox technologies will be based on the latest in IBM's family of state-of-the-art processors."
Microsoft's Xbox currently utilizes an Intel processor, suggesting that the future Xbox may break backward compatibility with the current crop of machines. (Unless, of course, Microsoft introduces some sort of emulation layer.)
Current Nintendo GameCubes utilize the IBM PowerPC processor, while the next-generation Sony Playstation is also rumored to use IBM-based technology (Cell). Apple currently uses IBM-based PowerPC 970 processors to power their PowerMac G5s.
Of potential interest, Microsoft recently acquired Virtual PC from Connectix which offers x86 emulation on the PowerPC.
