Batman Begins is not a part of the previous film franchise. It is stand alone, or a totally different interpretation of the comics, much in the same vein that the (p**s-weak) Catwoman movie was a different interpretation of the ilk in Batman Returns.
This is to be a 'fresh' start for the Batman franchise, and I don't expect we will see any Flourescent-light-fetishists Dr Freezes, zippy-dipsy Poison Ivy's or anything like that. Yes, there will be merchandise (there is for everything these days), but Batman Begins is a more sour-faced, dark and gothic approach, perhaps more so than what Tim Burton did for the franchise in the first two films.
The director has stated that this Batman the franchise has received a bit of a reality check, with a Batcape less than reliable as a gliding device, and maybe a more tank-like Batmobile would do better at fighting crime than a street-machine that has more bling-bling than what Snoop Doggy Dogg could fit on a fleet of Rolls Royces. This could well be the Batman as we need to see him; darker and edgier, instead of the poppy kiddie versions of Batman Forever and Batman and Robin.
Christopher Nolan is credited for Memento and was applauded for his ability to let the audience decide if a movie is good after the fact, not before. Something Joel Schumacher and Jan Dubont should have figured long ago . . .