Ineffective until there are some carrots involved
I hear claims all the time that IPv6 accounts for 30-40% of an ISPs traffic when dual stack is enabled. The reality is that 30-40% of the traffic is just a few big sites (Facebook, Google). Wider adoption is still miles off, and brings little advantage.
Until there is some reason to get your website IPv6 capable, IPv4 will remain - why would any sensible company fund a project without any tangible benefit. (For mega scale, simply address space management is a good enough reason. For small scale, not so much!).
The only way I see any rush to adoption happening is if google starts including IPv6 reach-ability in the search rankings.
On the "Showing everybody your address space" silliness, if you want to carry on NAT'ing traffic, well, there are plenty of firewalls, load balancers and proxies which will very happily allow you to do this for IPv4 and IPv6.