The only concern is how Windows 8 will fly on the desktop. That's obviously a big concern, but it's only a concern for people who can't imagine a touch-centric desktop.
It's exactly like people back in 1985 saying that Windows will never succeed because most MS-DOS users don't have a graphics display or a mouse. — Charles
Sums it up nicely, I think. I hear a lot of people saying "This sucks because it is all about touch. I do real work!" They need to start thinking towards the future, because I can definately envision a world in which we use gesture (think Kinect), mutli-touch (tablet-esque), speech, and even keyboard/mouse to create content.