One of Boeing's A160T Hummingbird UAVs has just passed an important milestone for the high-performance helicopter, exercising its two-speed transmission in flight and changing rotor speeds. This is something that no other helicopter has ever done, and that no other helicopter is designed to do, and is crucial to exploiting the design's potential.
Go here and here.
As I said about the X-47B being the single most important fighter/fixed wing project, the Hummingbird is definitely that for the rotary wing craft. Just behind it would be the tilt rotor C-130 replacement.