Voice control, IR blastering, allowing people to use Kinect while they are lazily sitting down, etc etc.The big difference this gen is voice control of the entire system. It could be quite compelling when people get it in their living room and it becomes required second nature control mechanism
They should pull a Nintendo; go with it no matter what, give some personality to the hardware. Nintendo never dropped the Wiimote, nor they are going to drop the WiiU's tablet.
Perhaps bkillian can shed some light on the subject, but I sense they never considered a Kinect-less console.