I have a Windows 2008 box set up with VPN, and that works quite well. NPS is used to validate the VPN clients, who are able to access the private address of the server, once connected.
I can't for the life of me get NAT working for the VPN clients, though. I've added NAT as a routing protocol, and set the one on in the VPN address pool as private, and the other as public - but it still won't NAT connections when I add a route through the VPN server's IP on the client side (route add SomeInternetIp IpOfPrivateInterfaceOnServer). I know I can reach the server's private interface (which happens to be 10.2.2.1) with remote desktop client, so I can't think of any issues with the VPN.