These guys, RP1, claim to have a huge breakthrough in big virtual worlds. http://rp1.com​

"What we’ve achieved is a system capable of handling more concurrent users unsharded than any existing system
can handle at full capacity. By eliminating limitations of concurrency, we’ve made applications possi…

Second Life, the big-world virtual world, has recently been ported to AWS. In the last few weeks, the first user-accessible test regions have come up. The old system is hosted at a colo in Arizona. The new system is running on AWS-WEST-2. 

The main result is that region crossings with vehicles …