I'm afraid I have to agree with Wormwood here. This thread got me thinking about Watchmen again, so I went back and read the trade paperback (for the umpteenth time) this week. I found myself paying closer attention to the tiny details, finding new meanings in things like the pirate comic, and again being blown away by how well-constructed the comic was, in terms of art layout, panelling, and even, for lack of a better term, camera angles. I'm afraid that without these details, these nuances, the overall impact of the story will be lessened. It will certainly be lessened by changing the amazing ending; that's really the only way it could have ended satisfactorily. It was that or WWIII.
Note to Hollywood: Not everything should or even could be made into a film. When you say, "This would make a great movie. We only have to change the ending. And get rid of this character, people won't identify with him. And change this character into a woman, we need more women to boost our box office," then you've already betrayed any pretext of art. Go find a property closer to your vision, or heaven forbid, actually come up with something original on your own.
Note to Alan Moore: You are already thought of as one of the greatest comic writers that ever lived. Stop letting Hollywood tarnish your image for a fast buck. Even a big evil company like Marvel makes movies more reverent to the originals, and respectful of their fans, than yours have been.