As a counter-example, I have watched the entire "command-line or death" development group at my company move from linux desktops and laptops to macbook pros ove

As a counter-example, I have watched the entire "command-line or death" development group at my company move from linux desktops and laptops to macbook pros over the past year. Linux desktops still survive, but as peripheral machines under desks that are not being replaced when they die or the hardware becomes too slow. The only people clinging to PCs are sales and marketing people who live and die in Outlook. As others have mentioned, the killer app for the Mac at the moment is being a unix box that "just works" and lets people get back to coding.