With LANs/WANs so geared toward IPv4 and NAT (not to mention the standard network guy’s ability to rattle off IP addresses from memory—try that with IPv6), I can’t imagine widespread adoption (exclusive) any time soon.
IPv6 is easy to remember, at least for addresses IT folks will be using a lot. Take loopback, commonly 127.0.0.1 (okay technically through 127.255.255.255, but people usually stick with that). IPv6 is even easier, ::1. And router configuration will get a whole lot easier.