Required reading for anyone who deals with networks:
The Future Without IPv6 and
IPv6 and NAT... Again!.
If we have any hope of getting out of the NAT trap how does IPv4 become painful enough to compel the transition? Will hitting NAT scalability issues be enough? Or will the attractiveness of forcing end-users to be consumers and not producers by making servers and p2p impossible through multiple layers of NAT mean IPv4/NAT will be attractive to upstream providers involved with media organizations? (Hello, Time Warner!)