Rosalind - 2:51 pm on Sep 30, 2010 (gmt 0)
So instead of thinking about Facebook beating Google in traffic referrals, think about Facebook creating their own mini-Internet, and reducing the need for anyone to leave Facebook.
That happens with Google and other search engines, and to an extent with any large website. It won't prevent users jumping ship as soon as the next big thing comes along. I'm seeing increasing referrals from Tumblr, and that's entirely closed off to anyone who doesn't join: yet another way to build a mini-internet.
Back to the OP, I don't think we'll see a huge surge in social networking vs. search engines. It's just that social is massively, massively consolidated right now. People used to go to various forums to connect with friends and like-minded people or to while away their time, but everything social is now FB and/or Twitter.