Spoiler
As for the fact that Two-Face dies in THE DARK KNIGHT, I have to say that I'm thoroughly disappointed by that news. For me, Dent/Two-Face was far and away the most interesting aspect of THE DARK KNIGHT, even moreso than Ledger's Joker. Two-Face has always been my favorite of the Batman villains, and while I do realize that the way that Nolan had set the character up probably didn't lend itself to having Two-Face as THE feature villain of BATMAN 3, I would have liked to have seen the character continue on for at least another film in some capacity.
The article that was posted about Oldman saying that the Riddler was available as a villain does raise the obvious point that the Riddler is the most likely villain for BATMAN 3. Given the fact that Two-Face can't be brought back (which is a shame, IMO) and the decisions facing Nolan about whether to recast the Joker (which I think he should as I would doubt that Ledger would want to have the character that he worked so hard to create just to vanish from the storyline), the Riddler is really the best choice for a villain that they have, apart from going down the route of doing the KNIGHTFALL storyline, which would be the only context in which I would want to see Bane featured as a villain. KNIGHTFALL, however, should happen much later in the franchise as opposed to this point in the franchise, IMO, so I can't say that I would be interested in seeing Bane in BATMAN 3
The article that was posted about Oldman saying that the Riddler was available as a villain does raise the obvious point that the Riddler is the most likely villain for BATMAN 3. Given the fact that Two-Face can't be brought back (which is a shame, IMO) and the decisions facing Nolan about whether to recast the Joker (which I think he should as I would doubt that Ledger would want to have the character that he worked so hard to create just to vanish from the storyline), the Riddler is really the best choice for a villain that they have, apart from going down the route of doing the KNIGHTFALL storyline, which would be the only context in which I would want to see Bane featured as a villain. KNIGHTFALL, however, should happen much later in the franchise as opposed to this point in the franchise, IMO, so I can't say that I would be interested in seeing Bane in BATMAN 3