@wkempf: I agree with not needing to go back to a Win7 UX. Having gone through the usability testing process a couple of times, I can say that you really don't have to make drastic changes (like bring back the legacy UI) to improve a user experience. Doing something simple like changing the color of a button can transform a completely clueless user into a more informed one. Additionally, you can add elements that encourage a particular mental model upon the user (e.g., affordances like knurling on the corners of windows or a row of dots, one for each page in the view).
Win8 really just lacks the elements that would guide the user into the right mental model. Once you know how it all works, it's pretty usable - it's getting to that level of understanding that is the issue, and something that can be easily fixed through simple indicators and in general making things more discoverable. For example, I really think they should carry over the three appbar dots at the bottom of WinPhone apps to show that you can swipe up for additional options. They should also flash the task and charms pane at appropriate times to indicate that it would be useful to swipe from the sides (e.g., flash the task pane the moment you open up a new app). Just simple things to fill in the gaps.