They could never tell what was happening with a networked printer, since hundreds of people on dozens of systems could all spool jobs to that printer. The system administrator responsible for printers began designing a scheme where all print jobs for a given printer went through one spooling machine. Now all of those 10,000 people around the world can print to any one of those 1600 printers anywhere else in the world, and all those print jobs are spooled through Linux machines. Corporate MIS wants someone to take responsibility. We all know Linux has incredible support through the Internet, but that's not the same as having someone's name on a legal document guaranteeing support.
Applications is another big one.
Ninety-five percent of the corporate world doesn't care what OS the desktop runs, but whatever OS it is, they want it to run the latest version of Microsoft Office. You can see the power of Microsoft Office in the recent deal Apple struck with Microsoft. Perception is one of the barriers I don't think people give enough weight to. The corporate world has to perceive Linux as friendly to corporate MIS people. The perception that Linux is for hackers only has to change.