The world has spent a long time on the road to native IPv6. Fortunately, protocol advancements have mitigated the arduous task of deploying the next generation Internet.
Essentially the software counterpart to the last-mile problem, deploying IPv6 to the CPE is “the last 90%” of the work. The core Service Provider networks have always been easier, and thus earlier, to receive both hardware and software upgrades.
One idea that has gained momentum is to use the IPv4 Internet as a point-to-point network connecting IPv6 “islands” through stateless, automatic tunnels.