I can reduce this Business Insider article to three charts and one sentence.
Instead of being the center of the personal computing world, in other words, the PC is becoming a specialized office-productivity device.
By the way, Blodgett never connects the dots, but it looks like Windows has only a few years before total obsolescence. IDC reported that PC shipments fell 11.4% in the second quarter of 2013, which looks like ~45% for the year.
Great graphs. The data tells the story.