Dave, this stuff was cited by Prouty about the AH-64 Cheyenne in Helicopter Aerodynamics. Cheyenne was a compound helicopter which settled on a seperate pusher prop after eliminating various alternatives. Having a pusher prop doesn't eliminate the need to do anything in autorotating, but it does give the pilot more choices. It makes sense to me that X2 would take advantage of these. I think you can also make out a rudder line on the X2 central vertical stabiliser.
http://en.wikipedia.org/wiki/AH-56_Cheyenne
Also i just noticed the use of NASC delta shaped intakes on the X2. I wonder if there is an advantage to be had here for spinning out debris from turbine ingestion. I've got X2 as my workstation backdrop, and it attracts a lot of interest. I think Sikorsky is onto a real winner with this project.