In case you're in the mood to read some more hands-on impressions of Skyrim's upcoming first DLC, the vampire-themed Dawnguard, RipTen is offering some from this year's E3. They don't seem enthused by the DLC's plot from what they've seen, but they claim the vampire gameplay is fun:
I had a chance to sit down with (Dawnguard) and experience a portion of the vampire storyline, as Bethesda remains very tight-lipped about the other half of this content pack, the Dawnguard. Despite my pestering, answers didn't come. So I moved on. I began in the vampire castle Volkihar, triggered some dialogue and eventually ended up in a realm plagued with restless spirits. I was able to experiment with the crossbow a little and found it easy enough to aim, but long reload times had me longing for my bow. I turned into a vampire and explored my catalog of creepy powers. Note that in order to use any of them, you'll have to press down on the right thumb stick and levitate, a fact I wasn't outright aware of, which led to my prompt and embarrassing death.
Round two: I turned into some bats, flew across the barren landscape, summoned a gargoyle, tore the souls out of my enemies, and flung magic around with ease while looking every bit the ugly, unwanted Nosferatu I'd longed for since Twilight up and ruined the stereotype. The vampire lord abilities do offer a dark sense of fun, and my preferred method of annihilation was by summoning said gargoyle. Vampire lords will also eventually be able to summon an undead dragon, and I can't think of any reason why that wouldn't be fun.