This video provides a good basic tutorial on how to use and navigate Windows 8 on both desktops and touchscreen enables devices. If you haven’t seen much in-depth examination of Windows 8 yet, check this out, it will give you a good idea of what to expect before you purchase a PC with the new OS installed on it.
Honestly, I still don’t understand why anyone would want to use touch on a desktop. I have several friends who have purchased all-in-one desktops with touch monitors, and none of them use it. It's not an OS issue, but an ergonomics argument, and the fact that you cannot comfortably lean forward at a desk all day to put your hands on a screen to navigate. Just like one does not sit on a couch and use a keyboard or mouse, one does not sit at a work desk, leaning forward for 8 hours a day, and put their fingers on a monitor. It's just plain uncomfortable and counterintuitive.
I don’t think keyboard/mouse is the end all of desktop computing navigation, but I also don’t think trying to force fit a mobile experience on the desktop is going to be the way to go either.
To be even more honest, I also don't understand why anyone would want mobile apps on their desktop. Mobile apps were developed because on small format mobile devices like smartphones and tablets regular web browsing was cumbersome and didn’t fit the form factor well. So with iPhone the mobile app sub-culture was born as apps were made to take advantage of the mobile touch interface that allowed web information to be more easily navigated and consumed. On the desktop, using a traditional web browser is the way to go, you get more detailed information, it's easier to use since you have the accuracy of the keyboard and mouse combo, and it is just a better overall user experience.
I'd be curious to hear from anyone who is using their desktop system with a touch interface full-time and what their experience has been with it. Do you find it comfortable for long periods of time? Is it more or less intuitive for you than a keyboard/mouse? Inquiring minds want to know.