A couple of things I could think of:
1. Planet exploration. Not in the same way ME1 did it, but maybe some sort of free roaming around larger cities on those planets?
2. Romance carrying on into the third game - Kaidan/Ashley/Liara returning, Garrus/Tali/Miranda/Jacob still being with you.
3. A choice of squad members. You have certain spots to fill (Tech Expert, Soldier, Biotic etc) and you could choose between 3 or so persons.
4. Background involvement. Meeting your family, childhood "friends" from Earth, a return to Mindoir. That'd be nice.
5. More ways to change your armor to suit your class better.
Then I'm hoping the game will let you play around in the world after you've saved it (assuming all galactic life isn't extinguished), with all reprecussions out there. Continuing as the hero of all organic species would be nice.
Then of course I'd like to lead everyone against the reapers for the very last final battle, but I suspect I'll get to do that anyway so I'll not add it on my list.
CloakedOne said:
Indeed: where are all of the female aliens? Female Turians? Female Krogan? Where are they?! They must exist, the Krogan don't shut up about them.
There's a Krogan female in Urdnot on Tuchanka. Called N-something, on the second floor in the same room as the Shaman. Pretty much looks like a male Krogan, only somewhat smaller and a higher pitched voice.