The Internet Engineering Task Force (IETF), which for all intents and purposes is the standards body of the Internet Protocol, has declared that “IPv6 is no longer considered optional.”
This has been coming for a long time, but because we have a generation of technologists that have been hearing IPv6 for ever, and it not materializing, people blow it off. No more.
As an interesting side bar, there was a great talk from Radio Free Asia last week at the OpenStack conference, and one of his challenges was not being able to get enough IP (IPv4) addresses in offices in Asia. Human rights software already needs to be IPv6 capable, otherwise you can’t install it in the locations you need it.