He is clearly delusion and a huge megalomaniac. Facebook in it's current form will not exist in 10 years. If they do, they will be similar to what AOL is today.
being long Facebook stock since the IPO, I take the opposite side of that bet . Facebook will be a bigger company even if it's slightly different. It's so huge and ubiquitous. It's not anything that can simply be a 'fad'. It's like a new medium of consciousness or fundamental integration with the world. The internet 10 years from now probably will not be too much different (the browser will continue to take over the desktop).