They haven't shown 'em, so it's hard to describe. Jim Merrick called them "bars". I'm not sure if that means they resemble
IR Blasters or what. I image they do, though.
But basically the little receivers are placed on opposite sides of the TV... creating a triangulated signal with the controller(s). This creates the position/motion detection in conjunction with the internal gyro. Supposedly the controller uses bluetooth for this. All 4 controllers would use the same 2 blasters, I'd imagine.