There is no spoon.
That's the best answer I've seen to your questions about decentralization and property rights in virtual goods.
Virtual worlds are like The Matrix. The answer to the question: “Who should own this spoon, the provider or the user?” is, there is no spoon. Once you understand this, the discussions of “virtual worlds” bring about an eerie déjà vu--“it feels like you’re in a room,” it’s a “virtual community,” we should have a “declaration of independence” for “new spaces for self-governance”. There is code, interface, and the social relations they make possible. There is no “governance of a virtual world.” There is simply the question of governance in the relations among users of a class of software platforms that have certain degrees of freedom in their design, resulting in a variety of social affordances, and therefore facilitating a variety of social and economic interactions.