It's a good teaser. Certainly better than some of the fanboy nerds are suggesting. Yeah, there isn't much new footage, but at least there is footage. Remember The Dark Knight teaser? There wasn't any footage at all. New or old. The end of this one with Bane coming at Batman like a man possessed and Batman backing away like a chump was pretty bad ass.
Since we don't know much about it, I think we should all try and guess what the plot will be. Since Bane is a character in the films, and in the comics he breaks Batmans back, and it also features the Lazarus pit, I'm going to say that at some point Batman gets his back broken by Bane, or gets severely injured/crippled and then it eventually gets fixed by the Lazarus pit. Rhas Al Ghul was a big part of the Lazarus pit storyline so with crap from him in the first movie being featured so prominently in the new trailer it's safe to assume he's back. At some point Gordon gets effed up. Possibly by Bane, maybe by someone else. Regardless, he's in bad shape, possibly dying. That could bring Batman out of retirement. Batman could be pissed and want revenge, but everyone hates him, so how does this work? Maybe this is where Catwoman comes in. She could have taken up the mantle while Batman was in retirement and protected Gotham City or at least protect it as much as Nolan would let a woman. The women in Nolan's films are always pretty weak whether it's Rachel Dawes in Batman who's always having to be saved or the girls in The Prestige who are always at the whim of the magicians (one of the wives drowns because she isn't saved), or Maude in Inception who's just a complete nutcase who can't even take care of herself and also needs to be saved, so maybe Batman saves Catwoman after she gets in too deep and that puts him back in the good graces of the people of Gotham.
Currently my most anticipated of 2012, and I hate comic book movies.