I don't think MMO is really the right characterization. It's probably the closest thing were used to today. It makes less sense as a "segregated game oriented w

I don't think MMO is really the right characterization. It's probably the closest thing were used to today. It makes less sense as a "segregated game oriented world", and much more sense as a shared virtual space, as in the cyberspace with avatars from science fiction. We have some of those today of course, notably second life, but an always-on persistent virtual world shared with everyone is a very different vision. It may have game-like elements, but to me that's not the interesting part. "I want a billion people to live partially in a virtual world in the future" seems plausible.