+1 for this - would've supported touch interaction with the buttons for people who didn't get the slide concept, but would've also supported desktop users much better than smart corners.
FWIW, I managed to get a play with a Samsung Series 7 earlier this week at an ehealth conference, and once you stick a touch screen on it (and an i5 under the hood ) almost everything becomes more intuitive (I say almost because app switching in Metro is, IMNSHO, borked. But that is very much an opinion). But the experience was smooth, intuitive, and it felt like I was using a touch screen device. Not convinced it felt like I was using Windows, though! But for a few very minor concessions to mouse navigation (see above), I think they could've made an OS that everyone could, at the very least, get along with - even if they didn't like it.
I wonder if it would be possible to make a laptop touchpad recognise swipe-in and swipe-out gestures - I can't think of any reason it shouldn't be, and that would mean on laptops you could easily bring up charms by just swiping onto the right side of your touchpad, close windows by swiping all the way down, bring up start by flicking up the bottom left corner - still wouldn't help mouse users, but would make Win 8 much more accessible on laptops...