Apparently Todd Howard was talking to G4 about vampirism and in the interview he said that becoming a Vampire will "completely transform how the game is played." At this point, all we know is that to become a vampire in Skyrim you have to catch the disease from an enemy vampire, much like in Oblivion.
He didn't say what exactly would be completely changed in game play other than taking sun damage and becoming more powerful as the disease progresses. Like in Oblivion, the player can feed on sleeping NPCs to control the level of vampirism.
All in all it seems to be exactly how it was in Oblivion. Maybe more specific details will come out closer to launch, but how do you guys feel about this? Were any of you hoping for a dramatic change to vampirism?