I've given Windows 8 an honest try on my dual monitor setup and it just isn't happening. Metro is out of place, consumes 100% screen real estate (meaning fast context switching between windows or monitoring multiple windows is impossible) and is constantly frustrating with its hidden controls and undiscoverable features.
The fact that they had to include Windows 7 in Windows 8 is proof enough that Metro is not suitable for the desktop. Windows 8 feels like a bizarre mashup OS that has no place on the desktop.