Seems like a way to cut down on helicopter hub drag, blade flex, and to unload the blades by loading up the wing-shaped disk instead.
If you'd retract the blades into the disk, it could go a lot faster than a common helicopter which is essentially limited by blade speed.
And DOH !
That's exactly the point ...
http://www.diskrotor.com/concept.htm
The disk rotor images are subsonic designs though.
And the tail rotor / fenestron is an anachronism .