It's all in here:
http://www.microsoft.com/technet/community/columns/cableguy/cg0902.mspx
Though there seems to be no way to make it auto-generate routes and issue them to interfaces, so if you're on DHCP you are relatively stuffed :(
Edit: Nothing a simple app to generate the appropriate netsh commands can't solve.
netsh interface ipv6 set interface "Internet" forwarding=enabled advertise=disabled
netsh interface ipv6 set interface "LAN" forwarding=enabled advertise=enabled
netsh interface ipv6 6to4 set state enabled
netsh interface ipv6 set interface "6to4 Tunneling Pseudo-Interface" forwarding=enabled
REM WWXX:YYZZ = decimal to hex conversion of WWW.XXX.YYY.ZZZ with two hex digits per byte
netsh interface ipv6 add route 2002:WWXX:YYZZ:1::/64 "LAN" publish=yes