"Batman Begins" is still in production, but "Batman on Film" has the first rumors about possible sequels. Their "Industry Insider" warns that you should take this as nothing more than rumor right now, as he says that this is some of the whispers he has heard about "Batman 6" lately.
Nolan is going to direct. He isn't signed (at least not "officially"), but it's no secret that the movie franchise is now "Nolan's Baby" as their source calles it.
The villian that seems to be obvious for the sequel, might not appear in the next film. The insider says: "They may want to build up to his appearance over the first two films - have him in the finale."
As everyone already knows, Christian Bale, Michael Caine, and Gary Oldman are set to return. Morgan Freeman will probably be back as Lucius Fox.
David Goyer will most likely be involved with the sequel. His status is much like that of Nolan's. BoF's source speculates that his role will be much like that for "Batman Begins" (writing the first draft and then Nolan taking over).
The sequel will probably not pick up right after the events of "Batman Begins". A bit of time may have passed between the events of the first movie and the sequel. Batman may be a bit more established in the follow-up.
The villian could be one that we saw in the previous Burton/Schumacher series.
Lets wait and see, how well "Batman Begins" does at the box-office. I hope it will be better than Warner Bros' latest Comic-Movie "Catwoman", so they make a sequel for sure. Then we'll know how much from this rumors will be realized.