I'm such a huge fan of movie trailers. In fact, when DVDs first started coming on the scene a few years back, I was so excited about the extras on the disks, that I imagined myself sitting on the couch, shuffling disks, watching nothing but trailers.
Trailers are very often better than the movie they're trying to sell. They're usually the most exciting bits, edited together in a much tighter way, and they often use music from another source that I like better than the actual soundtrack used in the film.
But the art and science of cutting trailers is quite specific. The perfect trailer will sell the film by giving away just enough of the plot, but not too much, while holding back some of the big surprises and plot twists. A good trailer will tease us with big names, beautiful cinematography, huge action or intimate gatherings. All in about 90 seconds.
I say all this simply to preface the fact that NPR's Fresh Air had a nice segment last week that tackled all these topics.
Also, there was a piece in the New York Times Magazine that dissected the making of the Signs trailer. Currently, that article is archived in their premium paid service, but you can read a synopsis here.