There's no way anyone who reads this blog hasn't heard about this yet. But just in case...here's a very interesting interview with Peter Larson who describes this find as - without undue hyperbole - "one of the most exciting dinosaur discoveries that's ever been made".
While you're at it, be sure to check out some of the other recently-uploaded videos from the Black Hills Insititute, featuring (among others) Bob Bakker and "Dino-Cowboy" (cringe) Clayton Phipps.
Update: Brian Switek (for it is he) has authored a blog post calling into question some of the more senstational claims made by Larson and the others. Go forth and read!