I'll have a full reply and rebuttal to all applicable comments in several days. At this point I'm too excited about TDK to get into a lengthy argument.
All I have to say right now is: to those who STILL somehow doubt Ledger's portrayal of the Joker, or to those who still believe Nicholson was more Joker than Ledger's portrayal is, I eagerly await what you will say after you see the movie, or if you will change your mind.
Nicholson may have been great for the time 20 years ago, just as Romero may have been great in the 60s (for the time). But the fact is that was then, and this is now. There was nobody to compare Romero's portrayal to in the 60s, and there was nobody else to compare Nicholson to 20 years ago. These were ALL different, varied portrayals of the Joker, some more accurate and some more definitive than others. To also say that Ledger cannot be compared to Nicholson or Romero is silly. Yes, they can and will ALL be directly compared, because they all portrayed the SAME character. No matter how different and varied these portrayals were, these 3 actors have all portrayed the SAME character.
I will bring up this thread in a few days, and will also bring up some of the comments doubting Ledger's portrayal after most here have seen the movie, just to say I told you so.