I have been plotting the IPv6 ASNs for some time. These should be the ISPs running IPv6. See: http://www.nlnetlabs.nl/ipv6/measurements/index.html
It would be interesting to see an analysis that combines this data with Geoff Huston's IPv4 analysis http://www.potaroo.net/ispcolumn/2003-07-v4-address-lifetime/ale.html and see if we can predict the point at which the number of IPv6 addresses deployed begins to exceed the number of IPv4 addresses deployed? I realize that the IPv6 analysis is routes only, but one should be able to determine how many addresses are available in each ASN. One could reasonably assume that at the point where the Internet shifts to IPv6 as the core protocol, more than half of the interfaces with an IPv4 address will also have an IPv6 address. So to get to that point, one could make some assumptions about the allocation of IPv6 /48's based on the observed trends in IPv4 /32's. I'm not sure where one would take this, but I think a lot of people would be interested in seeing some type of well-presented analysis of these questions. --Michael Dillon