did same test, got same result.under xp sp3 according to their faq the dns server is not ready or configured for IPv6 i`ll cross that bridge when i come to it..
For the moment there are a few ISP`s who offers native IPv6. If your ISP don`t offers IPv6 for the moment than you can try to use a IPv6 Tunnelbroker or you can configure Teredo under Windows to get IPv6 connectivity.
I did a little more searching and found that the only thing actually missing is the IPv6 DNS Server. An IPv6 address is already given in the configuration. So I suppose, we will just have to wait a while...
You don`t have to wait if you want to access IPv6 only websites. If you are using Teredo than you must configure a active route for this.
.. I will wait until IPv6 actually starts in June, then check again, and unless my ISP has updated the router, I will take it up with them... That should be the simplest way, I suppose.