[gregebowman]

Originally posted by atari_eric:
From what I've seen from half the Posts at Slashdot, producers tend to "borrow" themes from other movies for trailers, because often the real scores aren't recorded yet.

From what I know of movie soundtracks, this is true. Some composers, like my favorite, John Williams, will wait until the movie is complete and edited, then sit through a viewing and compose the movie afterwards. Other composers do it different ways. So there may be a soundtrack yet to go with the trailer.