Or, how about CCP?

They've both managed to maintain long-running virtual communities.

CCP might make more sense, but they still don't really have technology for building these sorts of worlds. I deeply respect them, and think that they probably have more appropriate tech to offer than most, but I think that one of the most important parts of virtual worlds is Second Life's original killer feature - content creation, which is something they have little experience in.

The ability for anyone to create is powerful, as recent games like minecraft have shown. Second Life just never kept up with technology, and now the best ways to create content for it involve the use of modeling software with a high barrier to entry. (Of course, it's terrible in many other ways, but that's a separate discussion).

If someone can build a virtual world platform from the ground up, with tightly integrated content creation that is intuitive (maybe something like sketchup), and all in-world, it would be very powerful.

I've actually been wanting to build just such a platform for a long time, but learning 3d graphics isn't the easiest thing out there :)

Microsoft's project spark looks like that kind platform.

How about a company whose whole thing is pushing the limits of tech to create a simulated universe: https://robertsspaceindustries.com/

As exciting as all this appears, you're looking at a 2016 release date a the absolute soonest; which essentially puts this project in the "vaporware until proven otherwise" category.

I could see that if it weren't backed by someone who's credible and proven. He didn't raise 41 million dollars for nothing.