CloudFlare provides a IPv6 -> IPv4 gateway. As a result, if you're on CloudFlare, your host doesn't need to have IPv6 support for your site to be available. You can enable the gateway for free. CloudFlare's DNS listens on IPv6 and will return a valid AAAA record when requested. If your host supports IPv6 then the connection is IPv6 end-to-end. If your host only supports IPv4 then the connection is IPv6 from the browser to CloudFlare's network, and then IPv4 from CloudFlare's network to your origin server. Here's more on how it works:

http://blog.cloudflare.com/introducing-cloudflares-automatic...

- A domain name with working AAAA records

- Your site reachable over IPv6

And possibly:

- Any software packages (Wordpress, phpBB, etc.) working correctly with IPv6