Just though this was interesting. The game Ilomilo, one of the most talked about (see video demo after the break), is a free download for AT&T Windows Phone 7 users. On top of that, it's an exclusive to the carrier as the game is not yet available in the Windows Phone Marketplace.
No word on how long AT&T has this game all to themselves, but if you were thinking of getting that Samsung Focus or HTC Surround, there' s one more reason. But it stinks for non-AT&T customers!