Shame about the desktop...
Its simple and I think the author worded it quite well; would I be interested in tablets and such then I'd be cheering because within that context I can honestly see Windows having the advantage, especially in an environment where there are already several Windows machines.
But on the desktop... that's a whole different beast. I get the feeling that MS bets on tablets and touchscreens overtaking the desktop, but quite frankly I don't see that happening anytime soon. Think about it; resting your arms on your chair, typing on the keyboard and all you need to do is move your hand a little to get to your mouse (or trackball in my case). vs. having to move your hand towards your screen and touch, click and swipe stuff. How long are you going to last doing that the whole day? Another issue; isn't that screen of yours getting dirty and more difficult to read this way ?
But most of all; the main reason why I don't get it is that MS should already have known that full screen is not the right way for the office. Did you know that Internet Explorer has a 'Kiosk' mode for quite some time now? Simply use the '-k' commandline parameter while starting and you see what I mean; fullscreen explorer (easiest way to try is opening up cmd.exe and going to \program files\internet explorer\. From there start "iexplorer.exe -k").
Its fun to play with, but unusable because you miss out on so much important information (the clock for one thing). This is supported from IE7 iirc (only tried it on 8 & 9 myself).
So why would a whole suite of fullscreen apps be any different ?