Re: RFC 2460..
"IPv6 deployment is *easy* "
Oh no it isn't.
As just one example, 128 bit addresses don't fit in any standard data type. And then there's the multitude of different textual encoding schemes. And the privacy and security issues. And incompatible MTU sizes. And the inability to coexist with IPv4 in any half-way sensible manner. Oh, and then there's IPsec and the huge great config mess that comes with it. Except that now IPsec is optional, so you've got a mixed network to sort out.
IPv6 is a mess, which is why adoption has been poor for so many years.