The latest TV spot for The Dark Knight focuses mainly on The Joker, who giggles a lot.  From the Chris Nolan article:

The director wasn’t interested in plumbing the murky origins of the Joker himself – the Clown Prince is more a Loki-like force of chaos. "He’s like the shark in Jaws," Nolan explains. "The Joker cuts through the film, he’s incredibly important, but he’s not a guy with a backstory. He’s a wild card."

THE JOKER is a WILD CARD?  Gosh, I’ve never heard it summed up so succinctly! Nolan went on to say that Duke from G.I. Joe "is a real aristocrat," before lighting up a cigar and adding, "ha ch-ch-cha cha cha."

After the jump I’ve also got a 9-minute "Gotham Tonight" Episode, "The Life and Career of Bruce Wayne". I’d only recommend watching it if you’re really, really bored. I watched it, but only because it was either that or listen to the rest of the voicemail my mom left me, the part in which she describes what her pets are doing at that precise moment.  "Now Tom’s looking out the window.  I think he sees a bird."