I've been looking at the advance screenshots of Windows 8, and so far my main reaction is: Why?
This style of interface is fine on my phone. My phone is small, has a touchscreen, and I don't do much in the way of real work on it. My PC, on the other hand, has a dual-monitor setup, does not have a touchscreen, and I need to do complicated graphics work and software development in multiple languages and IDEs. So, why does it need to have the same user interface as my phone? Why do I need to page through tiles when I'm not swiping a screen with my finger? I have a mouse and a keyboard and a whole lot of screen real estate. Why would I choose this paradigm? Why?!
It was bad enough when the monitor manufacturers decided that all I do at work is watch movies. Now, the Windows 8 desktop designers seem to have also decided that I don't actually work at work.
Well guess what, folks. I use fully-fledged applications, not apps. I use all ten fingers on a physical hardware keyboard; I don't peck out my code one letter at a time on a soft keyboard with overly helpful autocomplete. I do more with my mouse than drag prefab objects and poke a limited set of clickables. In other words, I WORK AT WORK!
Please, for the love of Turing, please don't turn my PC into a smartphone. I have work to do.