The Dark Knight Rises main twitter page re-tweeted this:
Supposedly made up of clips from Trailer #3 that is attached to The Avengers.
Also, the viral marketing is in full effect right now. There is viral graffiti at all the locations listed at TDKR main website. If photos are submitted from each of these "evidence" locations today, we will get to see the trailer early.
For your time:
TDKR TRAILER #3 (on post #27)