AT&T Uverse is deploying IPv6 to end users now here in South Florida with some of the newer modems. It appears to be via a 6rd tunnel on the back end, but it's transparent for the end users. This is an exciting and low pressure way to get familiar with it for engineers at home ( or tinkerers ). It has a stateful firewall by default, but can be disabled so you can use your ISR G1/G2 to gain more control over it :)