Well Two-face could be brought back. He would ruin Harvey's Reputation and Batman would be cleared of the killings, and therefore able to become the hero Gotham needs. But why would Two-face come back and his motif, I don't know. Would need to throw in another villian or two for sure. Black Mask seems like the logical evolution of the Mob - even if the mask is to only hide his identity. Penguin could aslo be a mob boss, but I've heard Nolan has already nixed him as a character. Catwoman would just be eye candy but not really a threat.
Riddler could be very interesting! Could even get away with not revealing who he is until the end - sort of a murder mystery type of thing. That could cause some caos equal or greater to the Joker! His riddles would be the only clues linking him to the crimes.
I think Two-face, Black Mask, and Riddler would be the perfect coice of villians for Batman 3. Maybe throw Scarecrow in again since he isn't dead?
Riddler could be very interesting! Could even get away with not revealing who he is until the end - sort of a murder mystery type of thing. That could cause some caos equal or greater to the Joker! His riddles would be the only clues linking him to the crimes.
I think Two-face, Black Mask, and Riddler would be the perfect coice of villians for Batman 3. Maybe throw Scarecrow in again since he isn't dead?