Check out RFC 4941, "Privacy Extensions". It's probably already implemented on the computer you're using right now.
IP isn't anonymous; it wasn't designed to be, and probably (given the problems it's trying to solve) shouldn't be. Anonymity should be an overlay.
I totally agree, though, anonymity is not part of IP. I was not implying that, just that there are still ways for home users to somehow shuffle their IPs within the IPv6 framework.
I get that the Tor Project is working on IPv6. But I also want IPv6 NAT, in pfSense or whatever. That's to keep my local device IPv6 addresses (hosts and VMs) private, even from Tor entry guards. I guess that it's time to learn how to ensure that.