While I didn't play 1.0 I'd love to at least see an update on what happened to the companions there even if it is just that they died. At the very least it gives closure for the 1.0 players on their fate in that case.

Outside of them I'd like to see a dragon-type companion as well, there was one sidequest in the Forelands where you became good friends with one of the little ones and if he were to "grow" up a bit more physically I'd say he'd have probably joined us.