Random point about this (my current employer is a national lab):
In 2006, the OMB issued a requirement that new DoD/DoE/USG/etc IT spend ("to the maximum extent practicable") be IPv6-capable, and tasked NIST with developing a testing framework for determining compliance:
Basically, we have to be IPv6-capable on external services by 2012, and be ready for it enterprise-wide (for anything that touches the Internet; offline farms, etc. are exempt) by 2014. I don't suspect many organizations are going to hit that, but that's the target, and we're taking it pretty seriously here.
Also, here's a random resource: a totally unofficial IPv6 survey:
http://en.wikipedia.org/wiki/List_of_assigned_/8_IP_address_...
Its a pretty interesting list of companies that still hold onto these blocks.