A level cap increase at least
Unlikely, but it would be nice. They could allow the skills your race gets a 25 in (Sneak for a kitty, archery for a woof elf, two-hand for a Nord) to max out at 120 or 125, maybe allow the ones that were 20 to starty to top out at 110. It'd be good for maybe three more levels.
Maybe when the "big" DLC they're discussing comes out, we'll get something of that nature. It won't matter much for me, since there are skills I don't use/level.
EDIT: Something else I'd like to se ethrown in with Hearthfire, or a future DLC at some point: hardcoe Mode. You have to eat and sleep, and hypothermia, fire, and disease can kill you.