There's a lot of concern about the role of PR in a Web 2.0 or 3.0 world.
I don't really believe them.
I think there will be a need for what PR can do for companies, even if print media continues to be replaced by online-only media.
BusinessWeek's current issue has an interesting story that supports that notion. Check out: "The Great Trust Offensive; Companies as diverse as McDonald's, Ford, and American Express are revamping their marketing to win back that most valuable of corporate assets."
I think social media belongs in the realm of PR, not just marketing or customer service.