Dual stack statistics?

[Erik Kline]

Sadly the slides link seems to be broken now...but IIRC

    http://www.internetsociety.org/events/ietf-84

had some content to that effect.  Comcast claimed 20-40% (reference
now missing unfortunately but may be in the video), and AT&T claimed
20% right after W6L:

    http://www.attinnovationspace.com/innovation/story/a7782696

"For our IPv6 enabled customers, we’re seeing more than 20 percent of
traffic transition to IPv6, which also speaks to the increasing number
of IPv6-enabled content providers."