No one is saying paid search or organic search is going away anytime soon, but Facebook is gaining traction as a legitimate traffic driver. A great example is last week's news that iTunes is offering songs by the Beatles. Apple discovered that on November 16 (the date of the announcement), 26% of their traffic came from social networks - normally that number is around 16%.
It wasn't long ago that people assumed that the way to drive traffic from Facebook to your site was to encourage users to "like" your Facebook page. However, it's users posting links in their status updates to sites or news that they find interesting that has become a powerful tool in driving direct traffic to a given website. Posting links directly in a status update broadens the visibility of a company or organization beyond its core audience and it doesn't rely on anyone having to "like" a page.
Perhaps this is the dawn of FBO (Facebook optimization).