Is it too early to start talking about the Batman Begins sequel The Dark Knight? I don't think so. :-)
Over at the excellent Batman on Film site there is already a fair amount of info about the upcoming Bat-flick, including the latest bit that an FX geek like me finds interesting in regards to the Bat-suit.
As in the prior Batman movies, the suit will continue to evolve, but I'm sure that in the current series there will be more of a logical reason for it to do so (beyond the latest costume designer wanting to but their "mark" on it).
According to BOF, the new suit will be sleeker and have more fabric to it, presumably to allow Christian Bale as Batman to move more freely. No doubt it will still have lots of armor on it, but it makes sense that a guy who fights predominantly hand to hand would wear a suit that allows for maximum mobility.
With Batman Begins having been so incredibly excellent and with the same director at the helm, I'm very excited about The Dark Knight. So far everything I've heard pushes this to the "good" side. A more realistic and creepy Joker as the villain, for one thing and even the fact that (so far) director Chris Nolan is being brave enough to not even put the name "Batman" in the title of the film. I don't know if that decision will make it all the way to the film's release, but I give Nolan points for trying.
The Dark Knight is scheduled to open on July 18, 2008.