I'm surprised that there hasn't been a thread like this yet so I'll start one now.
What further evolutions of Pokemon from previous generations would you like to see? Me, personally, I think there should only be expanded evolution lines of Generation V Pokemon. V was supposed to be a "fresh new start" so that probably assumed that the previous Pokemon were finished, meaning their evolution lines were set and done. Further evolutions of Generation V Pokemon, on the other hand, I would love to see.
I'm definitely expecting a pre-evolved form of Throh and Sawk, much like Tyrogue. Another evolution I want to see is one of Audino. It could be another Blissey and serve as a big blob of fat that just WON'T DIE (heh heh) but it could also serve as a BIGGER yield of experience than Audino. You thought Audino was a good Pokemon to get experience from? Well then, it's obvious that you haven't met its evolved form!