I ordered my 4-year-old computer with XP installed, specifically because a lot of the games I played still run well on it. A LOT of PC gamers stuck with XP for that reason. XP's popularity is the reason MS kept supporting it for as long as they did. My laptop runs Windows 7, and a lot of the changes seem more designed to appeal to people using computers for the first time. Windows 8 takes that to a new extreme and has a lot of compatibility issues with games. I won't buy another computer with XP, because, as Airwolfe said, support is running out, but there's nothing I use my home computer for now that requires a more recent OS.
Anyway, most models seem to prefer the MFC browser interface, and no one working on the internet, which covers most people, should spend money on a machine with an OS that soon won't get security updates anymore. I wouldn't be surprised if MFC discontinued support for their software soon, as well.