A "virtual book with Leap Motion" alone is easy to prototype. Windows 8 users, just install Touchless (use Advanced mode) from the Leap Motion App Store plus Kindle from the Windows Store.
The physical pages make things a lot harder. We don't support having the Leap Motion device pointing downward toward a surface, but we do support head-mounted mode. Arbitrary objects in the hand, such as paper, can interfere with tracking. You could mitigate this by making your physical page black, but then the picoprojector's image would be much less visible.
This nonetheless sounds like an interesting experiment.