just looked a bit more into the patent since some of the pictures of teh controller look quite different and found out the patent covers a few different options how to mix IR or visual trackicng with ultrasonic.
the final picture as an example puts the cameras in the controllers and uses an external refference point (you don't need the spheres at the controller with such a design). also in some parts the spheres are from a special material to make it possible to illuminate them with IR light and make them easier detectable with a infrared and visual camera (which alters between taking ir and vis images to increase precission).
also tracking of body parts additionally to the controllers with the same camera is covered.
on the question of the validity of the patent i can only say that that all these tracking methods allready exist and are in use for some years allready in Virtual Reality/Augmented Reality research (but also the wii was not using anything that hadn't existed in VR/AR research before). in VR/AR research you usually mix a few different tracking systems to get full 6 degrees of freedom tracking (position vector and speed/orientation vector tracking) and most tracking techniques have been researched since the nineties (some even longer than that). So the question with this patent is if this exact combination of these tracking technologies and the use of them for a gamecontroller is enough improvement/differences over other patents to allow it as a new one. But i don't have to decide this and it looks like patent agencies allso don't decide much since these days companies can patent everything and the validity of the patent will be tested in front of a court if anothr company thinks their patent is violated.
P.S I really think the whole patent system needs a big revamp, there is just too much abuse of patents going on these days.
