According to this Comcast blog posting, the MSO has begun its pilot dual-stack IPv6 deployment in selected markets. The first phase will support certain types of directly connected CPE, where a single computer is connected directly to a cable modem. It'll depend on the cable modem (a subset of DOCSIS 3.0 modems, which will expand over time) and operating system (only Windows 7, Windows Vista, Mac OS X 10.7/Lion), which must support stateful DHCPv6. Subsequent phases in 2011 and 2012 will support home gateway devices and variable length prefixes.