I’m sure by now most Bat-fans have read Christopher Nolan’s comments about returning to the franchise once more. If not,
“GB: Could you see actually yourself not making the third Batman film?
NOLAN: Well … let me think how to put this. There are two things to be said. One is the emphasis on story. What’s the story? Is there a story that’s going to keep me emotionally invested for the couple of years that it will take to make another one? That’s the overriding question. On a more superficial level, I have to ask the question: How many good third movies in a franchise can people name? [Laughs.] At the same time, in taking on the second one, we had the challenge of trying to make a great second movie, and there haven’t been too many of those either. It’s all about the story really. If the story is there, everything is possible. I hope that was a suitably slippery answer.”
I think the full interview merits a quick read-through. Definitely check out page 2 in which the director discusses his favorite scene in TDK.