Tranplanting a post from a thread I started, not having seen this one...
[snip] Personally, I think that they should combine the Daggerfall/Morrowind approach (clans or bloodlines with their own strengths, weaknesses and questlines) with the Oblivion system with the need to feed regularly (though Oblivion kind of messed it up having feeding making you weaker not stronger). Also, vampire hunters!
And for your consideration, here's a quote from Immortal Blood, a book in Oblivion, which discusses the vampires in Skyrim. If we get any of these powers to play with, I will be satisfied... But all of them would be better.
Quote
... He wanted to know about the vampires of eastern Skyrim. I told him about the most powerful tribe, the Volkihar, paranoid and cruel, whose very breath could freeze their victims' blood in the veins. I explained to him how they lived beneath the ice of remote and haunted lakes, never venturing into the world of men except to feed. [...] "Your advice helped me very much," he said. "But you should know that the Volkihar have an additional ability you didn't mention. They can reach through the ice of their lakes without breaking it."