>...change tact

Ugh. Change tack[1], which is a sailing reference[2]. As for the actual content, I feel this analysis lacks nuance. Mobile is booming, of course, but the PC is not dead, nor will it be dead five years from now. There are a hundred use cases for which a desktop or laptop is the only practical solution. Fantasize all you want about businesses abandoning real machines for iPads; reality begs to differ.

[1] http://idioms.thefreedictionary.com/change+tack [2] http://en.wikipedia.org/wiki/Tack_(sailing)