We lost our chance to avoid NAT's when variable length addresses were
removed from TCPv2.5 (IIRC the version number correctly).
or maybe when IAB was shot down after Kobe :)
NAT's are here, like it or not, and the only question is how to make
lemonade out of them.
see my other comment about magic pixie dust.
the way to fix NATs is to obsolete them. IPv6 is the best shot we have
at that.