Many organizations are in dire need of departmental NAT firewalls and VPN solutions. I had to beg, bitch and moan before a Pac10 uni would offer such a service to protect our users.
Actually all it takes is a firewall. As far as hiding hosts goes, a firewall is just as good as NAT. And then if you do need a host or two accessible, the firewall is easier to change than the NAT.