Spoiler:Didn't Nolan already say he finds the Penguin too ridiculous of a character physically to ever put him in a movie? I think he said that after Begins or maybe while he was filming Begins. Either way I kind of doubt we see the Penguin.
Bane is such a hard character in the Nolan universe also. Mainly because there aren't that many good actors with the physical attributes needed to play him.
I really think some consideration should be given to Deadshot. Like I already said he is Batman's polar opposite. He kills people, he uses guns. Two of Batman's biggest no-no's. Plus he's fairly realistic. The only issue is that he's an assassin and there aren't that many people left to assasinate after this movie.