I've read that the sudden and tragic death of Heath Ledger has brought doubts and questions as to the (up til now) impressive marketing campaign of The Dark Knight. The marketing has mostly dealt with Ledger's character of the the Joker, the trailer being a perfect example where the villain is center stage. Now that the actor who will play the famous and infamous movie villain has passed, Warner Bros. might tweak or change their marketing for the sequel.
Please don't. I don't think that his death and his portrayal of the Joker have anything to do with each other. Ledger's performance as the Joker will make him a superstar, and I'm predicting will lead to an Oscar nomination (predicted it before his death). Unfortunately now, Ledger will not see the fruits of his labors, but that doesn't mean anything should change in the movie or the marketing leading up to it. The campaign has been brilliant thus far and should lead to a promising return for Warner Bros. and the Batman franchise. Heath Ledger will have a lot to do with that.
(It's to be noted that I was one of the biggest doubters as to Ledger's casting. The 180 degree turnaround was completed with the release of the trailer.)