Game Pro: While I'd certainly recommend one of the Windows Phone 7 devices to fans of the Xbox 360, the fact remains that the software and app libraries are anemic compared to the iPhone. Where Windows 7 is able to gain some headway is with a unified UI and a dedicated library of games that manage to make mobile gaming a bit more rewarding. If upcoming firmware updates can make the touch screen a bit more forgiving, and the next generation of phones can eliminate the minefield of game-pausers, I might extend the recommendation outside of die-hard Xbox fans.
PROS: Xbox Live and Achievement integration make the mobile games mean a bit more; some of the phone's best games are Windows 7 exclusives; the unified UI makes it much less jarring to jump between programs.
CONS: Extremely ill-placed buttons will boot you from your desired program on many occasions; software and game libraries lack the depth of the iPhone's; some iPhone ports won't recognize your finger swipes as well on this platform.