So, you're going to give people their free software to run on their servers, and somehow get them to link servers, then get other people to connect to yours? I don't see that working out at all.
It's actually quite possible. I can see it happening assuming the server software is easy to install and maintain. It would also have to be pretty lightweight.
If you have a friend that runs the server, he probably has a few friends that run it, and so on and so forth. If you could get the ball rolling, so to speak, you could pretty easily make it an interconnected network.
I still see a missing gap with no centralized existance because there is going to be a disadvantage to people who have dynamic IP addresses that run servers, but it really shouldn't be to difficult to update... kind of like the DNS system... the server would have to update the other servers should it change an IP address and it would propagate throughout the system.
If I knew Java, I'd love to join this effort, but alas I do not. If you get it rolling and decide to publicly release it, I'd love to work on a website for it.
I think you guys should do it, it sounds like a neat idea!