What I have suggested before is a cgi script anyone can add to their website that a gnutella client can be set to post to every so often. Or have it try to connect to the Gnet every 4 hours and collect a few hundred fresh IP's.
If they also knew about each other, they could also hold a list of other list.cgi scripts available.
You get the point --- have a lot more static host caches out there, not just a few.
If you use your client every day you almost never have to connect to a static host cache anyway.
This is also one of the reasons I developed NapShare's automation feature so people would run their clients 24/7 and make the network more stable.