^ Uh... no they aren't. They actually addressed this. Moore asked them to do something for Bowling, and Stone agreed. But then he made it look like they somehow made an animation for the film, and some other crap, and I guess Stone was pissed off, and Parker was mad too. They aren't friends. In fact, I think they even talked about that a couple months ago on the Tonight Show. And come one, Team America? It doesn't get much more conservative then that... at least deep down, the satire is sort of subtle even though it has satire written all over it.
South Park is really conservative though... especially some of the songs the characters sing and stuff.