A recent study at Aachen University created a single-display multi-touch desk intended as one big, smooth work surface. They called it BendDesk. When tested with real users, however, they used the horizontal and vertical surfaces much as we currently use screens, mouse and keyboard - they treated them as separate planes and avoided the curved, connecting section like it was diseased.
Personally, if I had a desk like that, I'd be more likely to do my work on the horizontal surface, like a normal desk. Something else I'd like to see someone try is a tilted surface, like an architect's desk. I think that might turn out to be even better for large-screen multi-touch computers.
Mokalus of Borg
PS - I think the results indicate current habits more than fundamental psychology.
PPS - Maybe that's just me, though.