Ah, but they care about maximizing application compatibility more for some versions than others. Will microsoft care as much about app compatibility for windows 8 as they did for windows 7?
They sure don't care about IE 9 being compatible with XP. Breaking third party software and hardware is more of a pain, though, as Vista proved. That was most of the problems they had with Vista, but I guess they are over that hump at this point.
