People are overreacting on Windows 8. Yes it's different, but that doesn't mean it's worse. It takes a little getting used to if you used a different OS before, but that's the case with all new things, normally. Sure Windows 95 till 7 got the same GUI, basically. But trying something a little new isn't bad in days of touchscreens everywhere, even desktops have them...
What will matter will be real live performance (speed, stability) compared to Windows 7 and other OS and you can't tell much about those factors, yet.
However, with all those whiny comments going on I'd include an off-switch for the Metro UI parts of Windows 8, if I were Microsoft. Seems like people would have preferred just another Windows with the same look. 😛