Hi,
All TestBot VMs (with the exception of the Win9x ones) now have IPv6 connectivity. I was surprised that there was even a IPv6 stack available for NT4, it was produced by Microsoft Research. The VMs are (and always have been) behind a IPv4 NAT router. That same router now acts as a IPv6 router/firewall, with full outbound access but blocked inbound access. The website is also IPv6 capable, just waiting for the AAAA record to be added to the nameserver.
Greg.