Step one: make bendable, foldable displays a reality. Step two: invent an entirely new ways of interacting with and controlling digital interfaces that take advantage of their flexibility. The first is still in progress, but the FoldMe project from Germany's Darmstadt University of Technology has already gotten a jump start on step two. Instead of waiting for foldable displays to mature, they've developed some interface prototypes using projectors and IR tracking.
Their hinged book-like prototypes served as blank slates for projected displays that could detect the angle of a fold and react accordingly. In full landscape mode, like an opened book, two displays acted as one. When one side was folded over, a new screen presented itself.
The projection system in this prototype obviously presents a very rough approximation of what using foldable displays will actually be like. The quality there isn't really the point--the point is seeing how devices could automatically react to motion and improve user interaction. Watch for how quickly the foldable tool pallet transitions into a two-sided menu, for example.