Having played with the Release Preview I have to say that while Metro is
very cool, the bipolar experience of constantly switching between Metro and legacy (?) is very
not cool. I'm not sure if there was a better way to solve the problem or not (obviously Microsoft prioritizes backwards-compatibility), but right now it kills the experience for me.
If Metro apps take off we'll likely see the need to switch to legacy mode dwindle over time, but with so many of our common day-to-day apps living in legacy mode at launch I'm afraid Metro will just fade away in most users minds ala the OSX Dashboard...