Earlier quoted context omitted.
> That's never going to happen b/c there is too much legacy infrastructure and the benefit is marginal. It is going to have to happen, or there will be no internet. > All current home routers are configured to do NAT, so you're not going to be able to have a Skype 2.0 be P2P b/c then you'd need to explain to millions of people how to reconfigure their routers. Current home routers will be replaced within a year or tw…
You're also assuming that there won't be NAT with IPv6; I don't know that that is a safe assumption. "Current home routers will be replaced within a year or two." Yeah right! My grandma isn't gunna be changing her router. And she'll be pissed if her stuff stopped working. At then end of the day, if you have the choice between making a NAT friendly product that everyone can use and a non NAT friendly product that has…
It reduces, rather than increases security, since now the communication can be compromised by a security hole at either end (and NAT doesn't stop the machines behind it from being compromised) or at the exchange intermediating between them (which, most likely, neither party has any control over or detailed knowledge of the security practices in place on.)
And major ISPs are deploying IPv6 now: no mandate required.