It's basically back to the windows 3.11 days, that had no desktop either just windows with your programs in, metro is just this on steriods.
That's an insult to Windows 3, which offered much more flexible window management than Metro does.
Metro is more like a return to the days of Windows 1, where you weren't expected to multitask much and couldn't overlap windows (although in some ways even that 1985 GUI was less limited).
Don't see what all the fuss is about really, looking at metro I can see it's possibilities.
It's a crippled phone/tablet interface slapped on a desktop PC and it doesn't integrate well with desktop applications.
I use a couple of 27" monitors, one a pretty nice Hazro 2560x1440 display bought from OcUK. I didn't get them to run space wasting full screen apps designed to be more at home on a 10" touchscreen tablet.
People complain about Mac OS X, Unity, Gnome 3 and other new interfaces being dumbed down and a change for the worse, but Metro is the only one that scraps the 30+ year old idea of overlapping and resizable windows. I know that a lot of people just maximise everything, but personally I actually use the windowing in Windows.
Maybe given time Microsoft will make Metro more powerful, or integrate it better with the traditional desktop. But that assumes that Microsoft care about "power users", rather than tablet buying consumers, and that they want to preserve the traditional desktop rather gradually phasing it out.
What worries me is that there are plenty of ways in which Microsoft could have integrated Metro and the traditional desktop more elegantly. Instead they've chosen to make them very much distinct and inconsistent, with Metro non-optional and the desktop effectively running within it like an application. It makes me think that they see Metro, and applications that run in it, as the only future for Windows.
For now it's easy enough to stick with Windows 7, or just run desktop software in Windows 8, with Metro nothing but a fancy Start Menu replacement (which is one thing it does pretty well). That won't necessarily be true in a few years time, not if essential software and utilities start to become Metro only. If that happens then I will be looking at jumping ship to an alternative OS.