If a user could go to one server and get a list of rooms, users and games on all servers, that'd be very convenient.
Servers could use peer-to-peer networking to share information about what's running on them. When a new server is installed, it could "phone home" to the demo server. Servers, including the demo server, could save pointers (URLs) to other servers. When requested, it could go to the servers that it knows and then go to the servers that that server knows and so on and so forth. A RSS feed seems like a good way to export the information so that RSS readers and web sites (e.g. Yahoo!) could show running games without going to the server. A Twitter feed might be an alternative or an addition.