Eric Vyncke has implemented IP over Facebook with IPv6 addressing. The routers are click powered and use IPv6.
I stumbled over this paper were people had measured some aspects of IPv6 performance. It’s along the lines of earlier work, such as this, where you compare the performance of dual-stack hosts that you can reach by both IPv4 and IPv6. I don’t buy into all the conclusions, but some of the numbers are interesting. They actually found downloads faster over IPv6!
We held the Irish IPv6 Summit a few weeks ago. Niall and I spoke, and there was a good mix of local and international speakers, including Fred Baker from Cisco and Detlef Eckert from the EU. The slides and video from the talks are now available online from the agenda. Overall, we were pleased with the turn out and we’ve had some interesting followups as a consequence.