I wouldn't have the data spread around different servers cloud style, but virtualized cloud style private networks for SE might work. . It would work something like a raid setup. Put one virtual server in Japan that is basically the equivalent of what it takes to run the game (big servers like this do exist). Then put two others in place that run with it in two different parts of the world and if one goes down the other takes over. The involment of cloud in this plan allows for a few things:

-Less servers pulling electricity
-Servers in 3 different countries would work as I'd they were in the same network.

The downsides would be longer maintenance and God knows what other problems might occur when running an mmo on cloud.