It's a great relief that the CD doesn't seem to the R&B/rap-fest that was rumoured - considering the importance of underscore to The Simpsons, and with the relationship Hans Zimmer has with executive producer (and one-time guest voice) James L. Brooks, it's just as well. Kind of a shame that Alf Clausen didn't get to do the movie (Danny Elfman was never a plausible candidate, really), but what can you do? The work of Zimmer and his acolytes will be coming on Adrenaline next month.
I haven't seen any of the Harry Potter movies or read the books, but I do have all the soundtrack albums. Filling John Williams's shoes requires really big feet - let's hope this Nicholas Hooper fellow has them. Check out Soundtrack.net's First Listen to the CD.