It's very sad that Heath Ledger, a talented 28 year old actor and father of a two year old girl, passed away yesterday. It's foolish and pointless to provide conjecture over what caused his death, but I'm going to focus on his final project, and the unimaginable buildup that is sure to come. The Dark Knight was already being on it's way to becoming one of the most hyped movies ever, and now there will be this macabre pall over the release, bringing out the curious along with the fanboys.
The Crow would be a forgettable movie, were it not for the accidental gunshot death of it's lead actor, Brandon Lee, son of martial arts legend Bruce Lee. It would have to be considered a box office success, though, as well as in terms of rentals. Other movies associated with tragedy on set are Twilight Zone: The Movie and Apocalypse Now. Apocalypse Now managed to be of enough quality for the production issues to be a footnote, but Twilight Zone is primarily known for the three actors who died during production.
Apocalypse Now is a great movie, despite the difficulties encountered during filming. The Dark Knight hasn't really run into any apparent problems during filming, so Ledger's death shouldn't have an effect on the quality of the film. It will certainly have an effect on the way it is marketed, however. Although Warner would never come out and say it, but it's possible that there will be overtones of "the role that killed Heath Ledger" in advertising, no matter the autopsy findings. Or they could deemphasize Ledger in trailers and print, much like Miramax did in promoting Bad Santa with John Ritter. Ritter played a sizable role in the black comedy, although certainly not a lead like Ledger, but wasn't featured in trailers.
But the billion dollar question is whether or not this movie will gross a billion dollars. This movie was receiving the best promotion money can buy, and just received promotion you can't buy. When the Super Bowl ads roll, and you see however much of an unhinged Ledger that Warner decides to show, there is going to be an atmosphere around this movie that no one has ever seen. It isn't unreasonable to think The Dark Knight beats out Titanic ($600 million domestic). I'll guarantee it beats out Spider-Man for the all time comic book box office haul ($404 million). I will go so far as set the over/under for where it ranks all time in the all time box office at third.