after this flick, I don't see how there can be a sequel. I know nolan and bale are signed on for a third but they won't be forced to make one if there's no story. if two-face really is dead, than that's a shame. i figure he had to die because of the tremendous amount of suffering and demoralization he undergoes.
it really seemed like the "logical" end for him. like he was essentially a ticking time bomb. also, they portrayed him as a tragic hero more than pure villain, so a tragic death makes more sense.
Personally, I'd like to see a Nolan brothers + Goyer Knightfall arc. Make it work somehow. But in terms of direct sequel, I don't see how it would work. Not just as a story, purely superficial but also on a thematic level. seems like batsy has progressed in his characterization to the point of no-return. he's lost his last link to a normal life so he's JUST batman now. the mask is permanent