Just yesterday we were discussing internally at gogo6 why we thought Comcast was being so open with their IPv6 plans. We've dealt with over 50 top tier operators regarding their v6 plans and never has any organization been so publicly explicit. This article explains why: http://blog.comcast.com/2010/01/preparing-for-the-ipv6-transition.html
Turns out they are trying to galvanize an industry. They depend on various "stakeholder" to support v6 so they can support v6. More than this they will feed their experience back into the IETF to help shape the standards around the protocol. Pretty cool.