I think that you are also going to find that shops with any significant percentage of Macs that the shared services are run on Linux and not Windows. In a Windows-only shop you can basically get complete control once you pop the PDC, but in a blended/hybrid setup you are unlikely to be able to make quick lateral traversal to the servers that you would need to compromise to make the effort lucrative.

FWIW, I would bet that 25% or more of all enterprise Macs are also going to be running homebrew and a ton of standard unix software.