Guests: Director Zack Snyder, co-creator Dave Gibbons, and stars Matthew Goode, Malin Akerman, Patrick Wilson, Jeffrey Dean Morgan, Billy Crudup, Carla Gugino and Jackie Earle Haley

If last year’s big event was Paramount’s worldwide trailer debut of “Iron Man,” then this year’s must-see presentation was surely Warner Bros.’ big-screen adaptation of “Watchmen,” the supposedly unfilmable graphic novel by Alan Moore and Dave Gibbons. Joining director Zack Snyder on stage for a lengthy Q&A was his entire principal cast, and they spoke quite intelligently on the making of the film like a bunch of fanboys desperate to “get it right.” That didn’t come as much of a surprise to Snyder, since that was the very reason he agreed to direct the film as well. After all, whether the movie turned out bad because of him, or because of another director, he would always be the one responsible. Below, you’ll find some other highlights from the panel:

* The actors were so insistent on staying faithful to the source material that they often requested the dialogue be changed to reflect what had been written in the novel.

* Jackie Earle Haley received a lot of help from fans on how to play the character of Rorschach, right down to his trademark grumble.

* The only green screen used throughout the entire shoot were Malin and Billy’s scenes on Mars. According to Billy Crudup, it was far too expensive to shoot on the red planet, even with the backing of a major studio.

* Matthew Goode’s preparation for playing Ozymandis resulted in the actor giving his character a half-American, half-German accent – something that he’s not entirely certain will fly over well with the fans.

Of course, the real highlight of the hour was an exclusive sneak peek at the film’s extended trailer, and from what we saw – including everything from Rorschach’s constantly morphing mask to the beautifully-shot opening featuring the Comedian’s death – the film looks like everything it ought to be. We didn’t actually get to hear any dialogue, but the characters (as well as most of the scenes) appear to have been ripped straight from the pages of the novel. After seeing it twice, I can only say one thing: this movie is going to be a fucking masterpiece. Forget about “The Dark Knight,” because if “Watchmen” turns out even remotely as good as this newest trailer indicates it will be, Snyder is going to have a helluva hard time outdoing himself the next time around. I mean, what other challenges are left short of adapting “The Bible” for the big screen?