Batman Movie News and Updates was kind enough to take an article about The Dark Knight from the German Website Kino.de and translated into English where the filmmakers give some spoilers about the film:
*) Batman will go to Hong Kong for some kind of "gangster hunting", but the producer Chuck Roven won't tell us why Batman travels to Hong Kong.
*) The IMAX preview with I Am Legend is the first five minutes of the film.
*) "The whole thing is not 'Joker Begins', because we did not tell how the Joker became what he is", says director Christopher Nolan. "During these five minutes it is shown how the joker of the small crook becomes the most-dreaded gangster of the city - it is more of a "The Rise of the Joker"
*) Batman's new mask will have white lenses on the eyes when he turns on the Bat-sonar detection.
The Dark Knight arrives in theatres on July 18th, 2008.