Well, there’s P2P TV now. Why not a virtual world built on P2P technology?
There are no central servers at all: it only relies on end-users’ machines. Solipsis is a public virtual territory. The world is initially empty and only users will fill it by creating and running entities. No pre-existing cities, inhabitants nor scenario to respect… Solipsis is open-source, so everybody can enhance the protocols and the algorithms. Moreover, the system architecture clearly separates the different tasks, so that peer-to-peer hackers as well as multimedia geeks can find a good place to have fun here!
From networked_performance: Solipsis [via iDC]. The comments make good reading too.