NASA just disclosed design of their X57 experimental electric plane.
They too are exploring many small props rather than a couple of large fans.
The small props on leading edge are used for takeoff and landing, larger motors on wing tips used in cruise.
NASA's X-57 Hybrid Electric Research Plane | NASA
http://www.nasa.gov/press-release/na...umber-new-name
This one doesn't seem to have VTOL capability.
Yes, image is an artists impression.
Mickjoebill