I honestly believe the only reason we haven't long-since made the switch to Linux company wide was that the beancounters outsourced our IT support to an MS-only shop as a "cost savings". This was done by the same group that mandated secretaries and engineers got identical systems and couldn't understand why anyone would ever need anything more than the MS Office suite.
The stories I could tell...
You have 3200 seats at one site!!?? Where the heck do you work? I know what you mean about pointy haired execs making tech decisions.
"I put together a timeline for your project. I started by reasoning that anything I don't understand is easy to do. Phase One: Design a client-server architecture for our worldwide operations. Time: six minutes." -- PHB to Dilbert.