Google hosting Java webapps for customers?

This interested me. Why should Google be interested in making it easier to host Java programs?

Normally hosting Java programs is a problem for small people but not for big people. You can host lots of your own war files easily, but hosting other people war files is harder. Do you share VMs? If so, when one war file sucks too many resources it harms the others. Or, if you don't share VMs then you are going to need a HUGE server because each VM costs so much.

So it would be logical for Sun to be putting resources into fixing this problem - it would help Java scale down to areas that it it can't currently reach, and from what I can tell Sun was interested a while ago - Sun's project Barcelona was the birthplace for JSR-284, but the project it has been closed for a while.

But now Google seem to be putting resources into it. Why? Maybe Google, who are already getting into domain hosting, are going to be hosting Java programs with it?

Now that would be an interesting move.