This item over at Ars Technica is interesting. With the IPv4 address space nearing exhaustion, there has been increasing interest in and attention to converting to IPv6. This article shows that this transition is barely under way:
[The researchers] measured traffic flowing through almost 2,400 routers, amounting to no less than 4.5 terabits per second. The results: about 12 megabits of Teredo traffic, which was about 10 percent of the protocol 41 traffic, for a total of some 117Mbps.
The report cites studies that estimate the amount of native IPv6 traffic as 10 to 75 percent, so the total amount of IPv6 traffic would be 130 to 470Mbps. The measured IPv6 traffic constitutes 0.0026 percent of the total traffic.
... the Amsterdam Internet Exchange, which is one of the three big public interconnects between ISPs in Europe, does count native IPv6 traffic, which amounts to some 450Mbps out of a total of 370Gbps, or about 0.12 percent.