Do you think Skyrim will be playable with an Xbox controller for Windows immediately upon release? To play Oblivion with one requires additional software, with specific game packages, and even then runs into issues. Games like Deadspace 1 and 2 however have both provided full functionality. The game works for Xbox controller and mouse simultaneously from installation.
I hope so, that way I can play Skyrim on my HDTV with insanely good graphics. Oblivion didn't have controller compatibility but Fallout 3 did, so hopefully Skyrim will follow suit.