Warner Bros announced Batman Begins two weeks before the Comic Con in 2003, made TDK announcement a week after Comic Con.
Now that this year's Comic Con is over, so the question is: Do you think there will be Batman 3 announcement within two weeks?
If not, when do you think WB will officially announce the movie?
It could happen. Regardless of it being too early, or whatever, WB would be smart to ride the buzz of Inception and just make an announcement officially confirming once and for all that Nolan is indeed directing. And if they feel like it, throw us what the title will be. As a reference, here is an article reporting when Heath was announced as the Joker, July 31st 2006: