A lot of anti-MS folks are taking the following bandwagon:
“Microsoft’s lack of focus will be the doom of win8”
I don’t have a problem with the dual user interface approach. Why? Do I have a interaction designer insight from the future that allows me to think that? No.
There’s simply no way a company that has the level of success that MS has with Windows would do the “full blown change” to a metaphor that is clearly optimized for touch. It’s simply a irrational decision, at least for now.
If you look at this at the attempt to kill the iPad, as a simple, focused device this can be problematic (like Grubber points out here), but I see it as bolder, but similar step to the one Apple made with Lion: Integrating experiences.
I would dare to say that, looking at dual mode (windows 8) versus hybrid ( Lion and future osX versions) I prefer the former*. If Metro UI continues evolving like they are showing us, at this pace we will see a integrated MS system sooner than an Apple one.
*I actually don’t like windows regular UI… but you got the point.