I worked in an environment like this--500+ "desktops" running a mix of Solaris64, Solaris, SCO, SunOS, and HP/UX). We used cfengine, automounter, and a bunch of file servers for the different environments (compilers, perl, GNU utilities, etc.) NIS tied it all together. This was back in 1996. Why is this so hard for the OP _today_? If some marketing weenie needs Powerpoint, can't they run that on Wine?

Actually, M$ is opening itself up to lots of litegation in the UK and Europe. They better backpedle on this position i-fucking-mediately or they'll risk having XBoxLive banned in lots of European countries.