I'm definately going to see it. You can't really compare him to Jack Nicholsen though. Nicholsen played the funny/witty joker that you see in the original batman tv series, Ledger on the other hand is playing him as the dark and twisted joker from the original comics. Two completely different personas. There was an interview with Ledger before he died about the filming. He said that he got so immersed in the role that he wasn't able to sleep and was having really horrible thoughts as a result. That's why he went on sleeping pills, which led to his death.
It will be weird seeing the movie knowing that Heath Ledger is already dead. But I still can't wait to see it!
SICK MAN!!! I can't wait to see the sequel! I must be really behind....I didnt even know that trailer came out 0.o