The yet unrevealed funcion of the Wii

[Dyne]

Well on the IGN Wii-k in review podcast, they were talking about a little sensor that you'd put above your TV, and they were describing in detail the problems they'd have with it (TVs mounted in walls, etc.)

Based on the ambiguity of the sensor, I'm wondering if we really are going to see 3D visuals too, somehow. How did this "sensor" come to fruition, anyways? Was it announced with the Wiimote?