News that Chris Nolan is "thinking" about Batman "3" (after taking time away from Batman to make Inception, an automatic bomb simply due to Nolan's questionable writing skills) may make a lot of people really happy, but I'm not one of them. And hearing that his brother has already been "hard at work" on the script while Chris is only just now thinking about it is downright depressing.
The script for Dark Knight was written primarily by Chris and his brother Jonathan after David Goyer reinvented the franchise with Batman Begins. Goyer is a talented screenwriter that understands plot pacing, character development, and a whole host of other things that Chris Nolan does not.
Begins was raw character development from top to bottom, while Dark Knight had none to speak of. To the contrary, very little changed in the sequel that was too long, too focused on expensive action sequences that didn't move the story forward at all, and seemingly had no idea what it wanted to say or be. It felt more like a speed bump than a worthy followup. Replace Christian Bale with Jason Statham in Dark Knight and I don't think you could tell the difference between Dark Knight and one of Statham's mindless action flicks.
I blame that entirely on Chris Nolan. I like a lot of the things he's done, especially Memento, and clearly the man is a very talented director, but he was clearly out of his league when he and his brother took over writing duties for Goyer and now that they are dug in to the franchise like ticks, I don't see this franchise getting any better in the foreseeable future. If anything, it seems destined to go out spending $200 million one too many times and the audience will catch on that no, they aren't actually getting a real sequel to Batman Begins from the Nolan brothers. And then it'll explode in their faces and they'll both end up in movie jail for a while.