The one I'm most hoping for is Vector. I'd also like to see Quinn and Corso as SGRs. Can't say more because I've yet to play the other classes. (And I can't even play for a while, sucks to be a poor student :b)
I'd also like if I didn't have to start a new character to get the romance, but if it comes to that, I'm more than happy to roll my agent again, I really liked the character and the story. And dat voice.