Yes, I like that idea, however I am unsure of the details of how it would be implemented. Some pseudo-code might help explain, perhaps.

In any case it sounds like your proposal would allow for any ultrapeer to promote itself to a de-facto "dns" of sorts (excuse the improper jargon) if it has a lot of good hosts cached and would therefore allow the network to truly function as a -pure- P2P rather than relying on a designated/centralized server for it's host cache but would still maintain the bennefits of having a centralized hosts cache this way.

Some details on a specific implementation would be next I suppose and I would think that it would be especially important to target low bandwidth (i.e. modem connections) for the main ones requiring assistance from this type of system as high-bandwidth connections would not have problems finding peer hosts, as much, to begin with.

- max
max.weissman.com