The question, then, should be what do we do in the mean time? Would shutting down the YouTubes of the world actually hasten the advent of server appliances? I'm skeptical.

I also have trouble imagining how new social networking-type applications spread in a world where we have personal servers. The next YouTube/Facebook/Whatever will now have to write their software for a variety of different home servers (and there almost certainly will be a moderate-to-large number of incompatible devices), then convince people to install and correctly configure these apps, update them somewhat regularly to fix security holes, etc. Given the non-zero fraction of people who have trouble simply logging into Facebook, I think we're still a long ways off, and stand to benefit from the rich communities provided by simple, corporate-run networks.