Two-Face will be in the movie. I think they're gonna try to play it out like this:
-Joker throws a chemical substance on one side of Harvey Dent's face
-Joker will make it look like Batman did it
-Harvey Dent will buy it and hate Batman, but is still friends with Bruce Wayne. (He doesn't know who Batman really is)
-Harvey Dent will not recover pyschologically from the attack and will become Schizophrenic/Bi-Polar which roots from his hatred of Batman for ruining his life.
That's the thing about, Batman's villians they're all credible in how they orginate, except for a couple of exceptions (Ra's Al Ghul being one). Most of them have pyschological disorders and were mistreated as kids or as adults:
Penguin
Riddler
Two Face
Joker
Killer Croc
Poison Ivy
Freeze etc.
And now they lash out at society for there mistreatments and problems.
The whole Robin thing would be iffy........I mean the orginal Robin( Grayson) was supposed to be an acrobatic perfomer at a Circus with his Mother and Father. Some Mob boss/Crime syndicate leader killed his Mother and Father to show the owners of the Circus to show he meant buisness (Mob boss was extorting them for money), but that happens early. I think Robin is introduced in Detective Comics number 38 or 39, not too sure, but Robin is introduced after Joker and some other villains. So, the way I would like Robin to be introduced is, if they do more Batman movies, in the last Batman movie that feature Bale as Batman and Nolan as the director towards the end Bruce adopts Grayson.

That kinda sounds like I don't like Robin, but I think it would be for the best for the general public if Robin didn't really see any major time on the screen.