Batman Begins cast members have been talking about whether they've been signed to any potential sequels:
Christian Bale - Says that he is definitely signed to play the Dark Knight again. "We got a sense of who he is, but there's so much [more]. The psychology of the guy, to me, is fascinating. The guilt element you can expand on. You can expand visually as well. I haven't spoken with anybody about this, but I just really think it would be nice to come up with some kind of R-rated version, too, like a movie that is at one time PG and R, where you do two different edits for it."
Chris Nolan - He is not signed to direct any further films. "I don't really know. I did enjoy making this one. It's a fascinating character."
Morgan Freeman - "I'm not. I'm not sure that they really think that Lucius is an integral part of the series necessarily. But Commissioner Gordon absolutely has to be. Alfred absolutely has to be."
Gary Oldman - "I'm signed."
Michael Caine & Katie Holmes - Caine said of both of them "No, no. We're not signed." He then turned to Holmes and said "I mean, we'd do it, wouldn't we?" Holmes nodded affirmatively.
I just hope that Batman Begins is successful so do get these possible sequels!