As a matter of a fact I happen to own a WinPhone myself (Samsung Omnia W) and actually enjoy its usage. I wholeheartedly agree that Metro definitely has a place there.
But a 3.8" touch screen is hardly comparable to a 19 - 24 " static screen where the PC gets all its input from a keyboard and mouse.
Another important difference: On my phone the Metro screen /is/ the main interface. Because of its nature my phone only runs full screen (Metro) apps and nothing more. Bit obvious since you don't go move Windows about on a 3.8" display.
But on my 24" screen PC? My desktop (where all my stuff resides) is my main interface. That's where most of my stuff gets started.
WHY would it be a good thing not being able to start something as calc.exe and have it sitting on my desktop (where I also have Word & Excel) but instead being taken away from all that and get it full screen ?
I don't like having to use alt-tab all the time merely to type over a number which I've got through means of a calculation. That's not progress; that's totally absurd.