James, I think the analogy with American Psycho is a good one, as both novels were at least as much about the medium (or at least the style in the case of American Psycho) as they were about story, character, narrative, etc.
And I agree with you – Watchmen the movie won’t be a patch on Watchmen the graphic novel.
However, I ended up quite liking the film of American Psycho, mainly because Christian Bale managed to show Bateman’s desperation to be believed by his banker buddies much more vividly than I remembered it from the novel. I thought the ending of the film actually worked better than the novel did.
Watchmen’s won’t though. It will turn self-conflicted anti-heroes into cereal packet heroes.