In that case can anyone explain why the number of IPv4 *only* systems is increasing rather than decreasing: http://server8.test-ipv6.com/stats.html
Increased traffic from less-geeky people = more sane numbers overall. The problem with the graphs on that site is that the audience is self selecting; so only when some major site says "go here!" do we get a more random(ish) audience, versus people setting up tunnelbrokers and the like.
I would have expected the green+azure areas in those graphs to have increased in the past half year but counter-intutitively, it appears that IPv4 only usage is increasing.
You're assuming there's significant rollout of IPv6. Everything I've seen so far says that *starts* nowish, and more laterish this year, in any impacting way. Really, we're just just before the start of getting end user adoption to start rising.