Well, filtering through the white noise and hyperbole, he does make some valid points. I, too, think this is the end for XBox in particular and quite possibly Microsoft in general.
Microsoft owns more than 90 percent of worldwide computer usage (through various Windows incarnations), and Windows Phone is making significant strides against its previous irrelevance in the mobile space. The Xbox One has in no way caused any danger to Microsoft's existence, nor has the Xbox brand been damaged in any way.
Everyone was pissing and moaning about the PS4 and how nebulous that product announcement was (and we still know very little about it), yet now that Microsoft went through their own mild misfire (the only thing I disliked about today's announcement was the integrated Kinect, although I expected it; there is simply no way I'm going to speak, verbally, to turn on an entertainment device, no matter how much a company wants me to treat it like the main computer from
Star Trek), everyone is doing their best to piss on that, as well.
It's a game console. The purpose is to play games. Wait for the games.
Long story short: Calm down, folks.