Considering we now have Werewolves, Werebears, Weredragons, Wereyetis, Weremamoths, and Weresmilodon... What about Wereorcs? C'mon! That would be cool right?... Oh and like M'aiq said, Weresharks! And maybe a Werelich! Oh and!.. God have mercy on Skyrim...
WereWOLVES = Yes... Others? No... However, I honestly doubt they will have Werewolves. The only reason they were in Bloodmoon is because of
... Spoiler tags just incase somebody is playing Morrowind right now
So unless there's another something like that, which I thought they only happened every so many hundred years, then there would have to be another reason for them... Either that, or they be Extremely rare creatures... Then again, the rise of the Dragons in Skyrim may spark all the Werewolves to rise up, and see this as a 'final feeding' before the end of the world... Or perhaps the Dragons and Werewolves become allies? In any case, I don't really want random werewolves in random spawns. I want Werewolves to be hand-picked NPCs that are truly foes that you will fear. And maybe a quest where one of them invites you to be his/her Werewolf brother/sister/child thing? And obviously, the high chance of you just getting Lycanthropia* from fighting them, and surviving.
*I doubt that's how it's spelled, but that's the best guess I have.