I loved that music also! A quick check of the ever-reliable Soundtrack.net only produces:
Harry Potter and the Goblet of Fire (2005)
[TEASER] Harry Potter and the Prisoner of Azkaban (2004) - John Williams
[INTERNATIONAL] Original Trailer Music - Magic Box Music
It appears that Magic Box Music is the same as Brand X, which sounds familiar from other trailers.
Will see what a little more poking around can produce...
Edit: Just 'cause I can, download a copy (mp3 zipped). I also read through 4 pages of this very topic at a Soundtrack forum, but no new info. Looks like it's the curse of "original trailer music".