We'll see. TDK will definitely be a huge film, though it being darker less kid friendly, you're right it might not really kick spidey's ass at the B.O.
SR's in hulk's position now, though not exactly the same especially since SR's not an origin film or a new first ever movie for its hero like hulk's was. Still much like with hulk it didn't meet expectations for the studio and though when I visited here years ago there was, same as now, talk of universal willing to do another hulk, it never got made until of course as I learned, Marvel bought the rights to make the new hulk movie so now it's being done. Who knows what'll happen in SR's case... There will be a sequel of course, same as hulk. I always knew it would inevitably get one.
The only question is what are they doing, staying with ang lee's artsy approach or doing something different...