You need to manualy configure the IPv6 DNS servers to use. The servers are 2001:5c0:1000:11::2 and 2001:5c0:1001::194.
In Windows it is easiest to add the servers to the virtual tunnel adapter under Network connections.
I use gogoClient from Freenet6 in authenticated mode, and I don't need to do any server configuration !
Once I login to my Freenet6 account I just point my browser to ipv6.google.com and I get the jumping letters to confirm I have an IPv6 connection.
May be I am missing something on the question ?
You aren't doing that in 2010. And the the jumping letters is not happening any more. Yes you are missing going to the www.google.com without ipv6 in the URL and other sites on googles system all on ipv6. That is another animal altogether.
Yes, Jan, you would add that address to your list of DNS servers (/etc/resolv.conf for example).
On my router I'm running dnsmasq which allows specifying DNS servers for particular domains. In my case, I just added a line that directs queries for google.com to the v6 DNS address (currently HE's DNS because gogo's server still isn't answering my google queries).
My local DNS resolver is quite important to ensure efficient goeDNS lookups. I have just forwared the google zone in my DNS resolver configuration to a known Google IPv6 resolver and then the rest of my lookups are handled in the normal way.