I also don't think, MS will lock Windows and just use their own store. The post sounds very dramatic, but I couldn't imagine those drastic changes. I also don't see any reason, why I should swithc over to Windows 8 at the moment, my WIndows 7 platform is running rock solid and quick, why throwing that away? There are not such problems as with Vista, so no need to hurry.
And games running on Linux sounds far more unrealistic to me, as there are so many different version flowing around. This would cause a tremendous ammount of support for any serious commercial "game" product. And which company will take that risk? Those "handygames" may work, but a flightsim? I don't think so...
I think Windows 8 will not get that big thing and not so many user will switch over. I see no reason to do that...