Lots of interesting details about the hardware in the developer documentation:

* 6-DOF tracked controller

* Eye tracking

* Multiple depth of field display

* Persistent location tracking across multiple rooms

And limitations:

* FOV is going to be rather small

* Variable depth-of-field doesn't work well with objects less than a foot (30 cm) from your face

* Takes a few seconds for the system to adjust when you move real objects around (so if you move your couch, it won't notice instantly)