Unless, of course, there is some kind of an easter egg type of clue at the end of TDK like the Joker card in BB.
P
This actually seems like a strong possibility after what Oldman said.
Two-Face should be the primary villain in the third film, but they ought to use the Riddler. Yeah, that would be the same as Batman Forever, but if Nolan does come back we would get much more faithful and realistic incarnations of both rogues.
I'm sure Eckhart would want to finish what he starts as Two-Face in TDK. Nolan will probably come back for the third film, I think he just has other projects to do first, same with Bale.
