I saw the movie tonight....never have I laughed so hard at a movie in my life! The gags were plenty, and I loved the songs, backed by a "Big Movie Orchestra" instead of the synths used in the show. By all means see it...forget about Phantom Menace, Austin Powers, Wild Wild West; South Park BL&U is the one to see this summer!
The moments that brought the loudest audience cheers and applause:
(spoilers)
When the general shot Bill Gates
when Cartman launched into his stops-out rendition of "Kyle's Mom is a Bitch"
when Cartman screamed "respect my authoritaaahh!" as he obliterated Saddam
and...
when Kenny removed his hood. (Unfortunately, the cheers drowned out Kenny's only legible words...which nobody got to hear! What DID Kenny say?)