Here’s a draft (on it’s way to becoming an RFC) up at the IETF that describes how home networks could distribute IPv6 addresses obtained from an ISP.
http://tools.ietf.org/html/draft-chakrabarti-homenet-prefix-alloc-01
It’s nice to see some of this work finally being done! Also, while they say “Basic Home Networks”, by today’s standards, some of the examples are quite advanced (however that’s not saying it will always remain that way!)
UPDATE
As is often the case, this draft expired. However, it’s not forgotten as it’s been resurrected here