I'm teaching "Computer Programming for Non-Majors" this semester, as I frequently do. In past semesters, there have always been one or two geeky types with Macs, and perhaps one or two artsy types with Macs, among an ocean of Windows users. This semester, based on the students asking "does this program run on a Mac?" or bringing in their laptops for help with installation issues, I estimate that the proportion of Mac users is much higher than in previous years -- say, 25-35%.