I've been working hard recently on General Presence. I want to build a server I feel happy adding things to. Like it's fairly light and effortless to do so. We need more programmers who don't care about things like that that I have to clean up after later. Sadly, we have no money, so we can't afford to hire them.
Because the nature of the application is peer-to-peer (P2P), I've taken to calling 'servers' hubs. I envision user agents as generally being spokes, though they can act like hubs as well, they most likely won't nearly as much. I envision hubs having as many or more than 5000 active connections at a time. Some, very busy hubs, may have as many as 50000. I don't think user agents will ever have more than 5 or 10.
I want to be able to combine the efficiencies of centralization with the robustness and resistance to subjugation of a heavily distributed approach.