The trailer's been officially released:
http://thedarkknight.warnerbros.com/
I'm seriously looking forward to this flick next year.
They are reprising the role of The Joker and I was initially very skeptical of Heath Ledger taking it on. Jack Nicholson played The Joker in the original Batman and...well...Jack's just hard to follow. However, looking at the preview, I'm very intrigued and The Joker actually looks frightening. His laugh is pretty horrific too.
Of course, Christian Bale returns as the lead (as we all know).
Rachel Dawes is no longer being played by Katie Holmes, but rather Maggie Gyllenhaal. I'll be interested to see how well she does.
I'm definitely looking forward to it, and hope it keeps the same atmosphere as Batman Begins had.