I have also thought about this lately although not exactly in terms of being taken seriously as a developer but I am noticing more and more that, the "publicly seen" portable computer of choice is Mac OS X. In more and more recorded video tutorials, presentations(seminars)- you see the developer using Mac OS X. Sure I know it doesn't matter what you use as long as the job gets done. However sometimes you wonder why a mentor or someone you learn from change from say a Linux box to a Mac. You want to know what tipped the scale in favour of a Mac.