I challenge the usual suspects to deliver actual working dual stack IPv6 ADSL CPE rather than feigning interest. None of the major CPE vendors appear to have a v6 plan despite your claims. We have an IPv6 dual stack trial for ADSL going on and not a single CPE from the _major consumer CPE vendors_.
I've saw some ADSL CPEs that could bridge specific frame types. It would be feasible to think of an ADSL CPE that would simply bridge IPv4/ARP and IPv6 ethertypes and have a dual-stack BRAS service the users, or bridge IPv4/ARP to a VC(Virtual Circuit) and IPv6 to another VC, or NAT+Route IPv4 to a VC and bridge IPv6 to other VC. In an IPv6 world where NAT is not a requirement (paranoids are welcome to buy their own IPv6 firewalls), bridging with some L4 intelligence might be all that a CPE needs to do. The IPv6 idea of letting end-nodes have more work and intermediate nodes have less work also applies to CPEs. Rubens