things I like about Dawnguard:
the Darth Vader Grip, if it adds "choke" animations I'll be pretty happy

The fact that we can hover as a vampire.
Bat "dodge" or whatever, hope Npcs can use it as well
Things I possibly want
good old sun damage. please. no more sparkly vampire thing, make us WANT to blot out the sun (and fix lunar damage as well)
moddable vampire perk tree
much more powerful dragons
revamped shout system, dammit. more power and more usability!
Stuff I want in the next expansion packs
-become a lich
-become a DRAGON!