I also suggest test-ipv6.com which gives interesting results and feedback
For exemple, today while looking to replace my DSL modem local DNS server for different reasons (http://en.blog.guylhem.net if you want to know) I realized usual DNS servers such as 8.8.8.8 or 4.2.2.4 couldn't work for aaaa.v6ns.test-ipv6.com.
Yes I know, using 4.2.2.4 makes baby jesus cry, but it was easy to remember and faster than 8.8.8.8. Yet now I've got a new favorite - ordns.he.net
Try it for yourself : dig aaaa.v6ns.test-ipv6.com at your favorite server and see if it works.
I assume you just mean that test-ipv6 gives you the warning:
"Your DNS server (possibly run by your ISP) appears to have no access to the IPv6 internet, or is not configured to use it."
I get that too (I have IPv4/IPv6 connectivity)
I really wouldn't worry about it too much. We're FAR from the day when anybody could contemplate publishing their public DNS zones using just IPv6-only nameservers. Therefore a recursive IPv4-only server will continue to work for a LONG time.
The more immediate problem is publishing servers running IPv4-only (making a fully-recursive IPv6 only server impossible) The good news is that the large DNS-providers seem to be mostly on the ball about this. There are, however, still a few TLDs with IPv4-only DNS (.co is one example)
For exemple, today while looking to replace my DSL modem local DNS server for different reasons (http://en.blog.guylhem.net if you want to know) I realized usual DNS servers such as 8.8.8.8 or 4.2.2.4 couldn't work for aaaa.v6ns.test-ipv6.com.
Yes I know, using 4.2.2.4 makes baby jesus cry, but it was easy to remember and faster than 8.8.8.8. Yet now I've got a new favorite - ordns.he.net
Try it for yourself : dig aaaa.v6ns.test-ipv6.com at your favorite server and see if it works.