Google recently opened their Wave server for federation, meaning that anyone can download and deploy a Wave server.
How much 'server' is required to run Wave for a given number of active users?
I understand this is a difficult estimate to make, but I'm hoping that someone will have some metrics. If not now, then soon.
Java has increased in speed and performance, and I'm certain Google has been coding for speed, so I'm hoping that one can run a small wave server on a VPS, and a reasonably sized Wave community would only consume a single dedicated server.
But currently email servers can handle tens of thousands of users per mid-range server, and I'm worried that wave will require more than a single order of magnitude greater resources.