At the RIPE meeting in Dubai two weeks ago, Google presented results from a study about how IPv6-capable "ordinary users" are. And the results are surprising. While an earlier study by Arbor Networks showed only 0.0026 percent of all traffic was IPv6 enabled, Google determined that world wide, 0.238 percent of their users' systems have IPv6 enabled and prefer to use IPv6 over IPv4 where possible.
The results start getting more interesting when correlating IPv6 use with country. The top five IPv6-using countries (that generate significant traffic) are: Russia (0.76 percent), France (0.65 percent), Ukraine (0.64 percent), Norway (0.49 percent), and the US (0.45 percent). The notion that IPv6 is much further along in Asia is apparently a myth: China showed 0.24 percent IPv6-enabled users and Japan 0.15 percent.
Source:→ Ars Technica