Wiimote MotionPlus accessory as "that thing that makes the Wiimote work the way it should have in the first place." But as it turns out it may also someday be "that thing that makes the 360 controller or DualShock 3 work the way the Wiimote should have in the first place." InvenSense, the company behind the tech, says that Nintendo doesn't have the exclusive rights to it, and that other companies have expressed an interest. To be fair though, they don't name anyone specifically.
So, Nintendo, out of curiosity: You invest in an addition to your console's primary feature and you don't even lock up the rights? How about you dig through Miyamoto's office cushions and buy the exclusivity, the company and a gold-plated hover-castle for them to work in? What are you saving for?