Not a peep about the game so far beyond he "Deep Dive trailer". No one at Square said anything at E3 -- even when I asked behind closed doors -- and the only thing the Disney Interactive (or whatever they're calling themselves now) just said "It could happen."
I know for a fact that the director, and much of the development team, of the first one is busy with a different project right now and neither company wants to go ahead with the project until they're all free. He has always said in interviews that it would be sometime in 2004-05. Kingdom Hearts was in development for about 3-4 years (development started in 1999), so either way you've got a wait in front of you.
I'd guess the safe bet would be to say that you'll hear something about KH2 before the end of next year's E3.