Surface design issues
Surface presents some interesting problems with UI. One is how do you handle large scale datasets? For example, my digital camera has a 4 gig SD card for storage, which can hold about 1200 photos, what happens when 1200 photos "spill" out onto the surface? Could you imagine having to manually move around 1200 photos? Yikes!
So I believe that filtering and search tools would be needed in Surface to handle the data load that we all have (and create / crave). For things like photo apps, I'd create or like to see stacks, treemaps, sparklines, zoomable interfaces and I'd like to see some visual search tools. These search tools could be keyword searches like (person, tree, dog, food) or a simple drawing search interface (InkCanvas anyone?) like a smiley face for a person's face with a smile. Granted there's big money and big and small companies working to solve these however, I think the Surface team will have to deal with some sooner than later and they'll have to tools / interface to make it work.
I'll post some scans from my Moleskine as soon as I get my old Dell A940 all-in-one to play nice with Vista.