wouldn't bother me personally (everyone's got to get theirs), but i could see it presenting difficulties. right now they have the lofty position of being fairly irreverent to whatever brands they like, as they don't have any obligations to anyone. i don't think they'd necessarily lose that position entirely, but from an idealistic standpoint, it would limit their behavior. can't take a brands money, and then slag them on air.
it's like bands' music in car commercials- it doesn't directly offend my sensibilities, but there is a dilution of the creative work that occurs as a result.
again, it wouldn't freak me out, but it is one of those things that once you start, there really isn't any going back. perception-wise, anyway.