Perhaps. The data may have "left the barn" but all updates to that data are done through Facebook itself. People are really bought into Facebook, I don't see it

Perhaps. The data may have "left the barn" but all updates to that data are done through Facebook itself. People are really bought into Facebook, I don't see it going anywhere anytime soon. That said, Friendster failed, and so can Facebook (and even Google). It will just take some time, and something pretty unique, to replace it.