I played with 3 Win8 touchscreen computers at a store the other day. The big 'all in one' one - from HP I think - was just not good. You might get used to it, but I didn't like it. The dragging - which you end up having to do a lot of - was pretty slow, and no amount of poking around in the system settings showed a way to change the responsiveness. Secondly, it doesn't seem that there's any sort of speed sensitivity…
I think in terms of Windows 8, the new touch screen is easier to navigate and interact with using touch than it is with keyboard and mouse. And feels more natural.
I think the keyboard & mouse experience could be improved.
An example, my brother installed Windows 8 on his Lenovo Thinkpad the other day and took a good few minutes trying to find the shutdown button until I showed him where it is now. (Hover right to bring up the charms, select power. Or press ctrl+alt+delete. Or if all else fails, pressing the power button should shutdown the device).