True! That's what I ment with they take the weakest and most attractive. So this will deny your thesis, that any kind of protection will endanger Gnutella.
I wonder that you do not believe in Freenet ideas. However the "Freetella" ideas describe more guerillia countermeassures like rerouting of small parts of traffic (would be possible with swarming, okay I repeat my self, sorry) and more ideas could be envolved.... think positive/constructive.

Nice and friendly today? But you brought up a not so far mentioned point! Mutated Gnutella programs/verisons, be honest: This means Gnutella must not only be a open protocoll, the client must be open source too and the main developers must be strongly protected agains lawsuits. So this also means a new kind of thinking inside Gnutella... open source and more cooperative behaviour... awesome!!!.... since months I'm looking forward to that day (what about Vinnie?).
In open source servants I see indeed one of the _best_ strength of Gnutella (bye bye proprietary clients)... thx for mentioning it!
In that context I hope the developers community finds an agreement about anti freeloading - or together with more upcoming multisegmented download servants Gnutella will kill itself IMHO.