I fail to see how introduction of new IP version numbers and packet
formats will help anything at this point. The operational timescales
involved are staggeringly long.
IPv6 deployment is certainly "unevenly distributed" at the moment, but
basically all the trends are "up and to the right". See the World
IPv6 Launch measurements website as well as all the published data
from Akamai, APNIC, RIPE, and Google. The following polynomial
extrapolations of Google data suggest that global IPv6 adoption will
be north of 20% by the end of 2017 and around 35% by the end of 2019:
https://www.vyncke.org/ipv6status/project.php?metric=p&timeforward=1280&timebackward=1280&country=ww
Bear in mind that those are global average numbers, and some countries
(hello Belgium) are already at 50%.