good music. good movie?

bloc party

I just found out that the upcoming summer comedy, Wedding Crashers, actually is going have one of the best soundtracks since Garden State: Bloc Party, Death Cab for Cutie, Rilo Kiley, Flaming Lips, Jimmy Eat World. I'd like to know what inspired all these folks to collaborate on this one album soundtracking a movie about wedding receptions and the guys who hawk them for bridemaids. I know it will probably be funny, but it seems a bit odd.