I'd rather work on my 24" Monitor with a regular mouse and keyboard, and for that I would appreciate the option to disable the Metro gizmo completely.
Don't get me wrong, I own a windows phone and think metro is great for touchscreen devices. But forcing metro on the desktop is the wrong move by Microsoft IMO.
If it all goes horribly wrong I could even imagine users being so disgusted by Windows 8, that they won't even try the upcoming Windows Phone 8, even though that is the correct environment for Metro.
Or maybe im just thinking everyone is like me :P and I shouldn't project my view on others.