This phenomenon, usually called 'trailer remixing', is becoming increasingly popular. Personally I think the guys who did "10 Things I Hate About Commandments" are the best out there at putting together these things. You should also check out their first one, "Must Love Jaws", it is great.

Some others I've seen:
Titanic (as a horror)
West Side Story (as a horror)
...and the same page that links to those 2 mentions a "Sound of Music (as a thriller)" unfortunately however, it didn't have a link and I couldn't find it.