True Peer to Peer

I've got some questions about True Peer-to-Peer networking. I don't consider Napster True Peer-to-Peer (TP2P) because it relies on a centralized server. I predicted, when I first heard about it, that Gnutella would become a victim of its own success. That TP2P, given the conventional way of thinking, was going to be plagued by the limitations of the last-mile connection. Since wireline-56K is still the predominant connection type, there was undoubtedly going to be scalability issues.

Then, Gnutella hit the wall.

Response and transfer times degraded drastically. A theoretical limit had been reached. What was great about Napster was that because it was the most straight-forward implementation of P2P, the connection from peer to peer was only necessary for the actual transfer of information. The central server holds all the "routing" information and the only overhead was in querying this central server.

In TP2P, you've got the querying going on in addition to the transfer. Everyone who logs on will presumably send out queries. Taken to the extreme, can you imagine if your computer "heard" every query from every other computer on the network? Even if you split the Gnutella network into sub-networks, you'd hit the scalability wall eventually. I haven't kept up to date on the advances in TP2P, so my question is: has this scalability issue been addressed? How would you address it?