PS: Don't forget there are even more ideas coming up, like Superpeer, Swarming and Hashs!
PPS: Hashs at the GDF are called "HUGE" (Hash/URN Gnutella Extensions), e.g. link 1 link 2
PPPS: Here is the current (old) version of the Gnutella Protocoll http://www.clip2.com/GnutellaProtocol04.pdf ...and TCP will be still used.