I'm using a samsung Q1 7 inch touchscreen computer with circle dock. It's pretty nice so far.
With a little work, a touchscreen with circle dock could work like this:
Tell me that isn't a dreamy thought! The few things you'd need really are animated dock backgrounds, the option to cluster icons a certain direction instead of them spreading out as far as possible, Folder expand and contract when pulled away from and towards the center button respectively, and rotating icons by grab and drag.
Ultimately, you'd have a pretty bad ass dock that blows the competition out of the water.