Here's an interesting rumor doing the rounds today. According to Xbox Evolved, Microsoft is exploring the possibility of "forward-compatible" games for the next edition of its Xbox console, which basically means that when you play old Xbox 360 title on the newer machine, it'll be enhanced with improved graphics, better speed, a new button scheme to fit the new controller, and possibly new features.
The site compares the jump to playing Crysis on a mid-range PC, then updating the video card for better performance. Microsoft is supposedly in a stage of "testing the waters" with this feature before they nail down the final specs of the next Xbox, but wants to put this option out to developers soon so they can implement it in their upcoming titles. Of course, this is all speculation for now seeing that the next generation of consoles is not expected to arrive for a few more years. It certainly sounds like a cool concept, though.