Is THIS how you imagined the vampires?

[Beanamir of Gondor]

Tolkien does seem to differentiate very much between the "Nosferatu-vampire", as Morthoron put it, and the "vampire-bat". I looked over the text everyone was talking about again, and my edition of the Silm (second edition, Christopher Tolkien, Del Ray paperback) there's a specific distinction between Luthien taking on the "vampire" form and Sauron taking it on:

The Silmarillion, Ballantine Edition p. 207
Then Sauron yielded himself, and Luthien took the mastery of the isle and all that was there; and Huan released him. And immediately he took the form of a vampire, great as a dark cloud across the moon, and he fled, dripping blood from his throat upon the trees, and came to Taur-nu-Fuin, and dwelt there, filling it with horror.

To me, the dripping blood and great as a dark cloud across the moon definitely, definitely indicate some kind of Stoker-ian vampire. Wasn't there some piece in Mina Harker's diary about a shadow across the moon? (I'll be back to edit this, I don't have the book with me right now.) Besides, the dripping blood from his throat evokes Dracula, even if it was just Huan's attack that left his throat torn.
Then there's the section with Luthien, which I take very differently:

The Silmarillion, Ballantine Edition p. 211
He turned aside therefore at Sauron's isle, as they ran northward again, and he took thence the ghastly wolf-hame of Draugluin, and the bat-fell of Thuringwethil. She was the messenger of Sauron, and was wont to fly in vampire's form to Angband; and her great fingered wings were barbed at each joint's end with an iron claw.

Now, not to pick nits or count straws or anything, but that paragraph doesn't necessarily say that Thuringwethil's bat-fell was necessarily in vampire-form when Luthien put it on. All it says is that Thuringwethil was a bat, and that sometimes she flew to Angband dressed as a vampire.
Now, Morthoron made the distinction between the "vampire bat-fell" and the "Nosferatu vampire form". I think we're working with far too little text and way too many English majors, but it could be that the Nosferatu form, the one Sauron took with the dripping blood and the great black cloud, also had great fingered wings.

In that David Day edition that sallkid was talking about, there was also an illustration of vampires. I wish I could find the illustration--my favorite used bookstore has a copy, next time I'll just walk in and buy it, and scan the picture in. But anyway, the vampire in that particular edition looked a lot like the original Nosferatu. Of course, that was all heretical pictures created by an unauthorized artist...