I think the dual IR could also be for tilt detection for the pointer, as wii doesn't seem to pay much attention to the relative distance (like Nintendo said to themselves, "nah, no one cares for perfect accuracy, let's leave out the option to calibrate the pointer by entering your TV size"). But the wiimote measures tilt with the gyroscopes also, so it doesn't really seems neccesary. I guess next time I'll try putting the sensor bar vertically and see if the pointer gets tilted.
Specs: intel i5 3570k @ 3.4GHz;
16Gb RAM; Raedon HD 7900;
Win8 64-Bit
16Gb RAM; Raedon HD 7900;
Win8 64-Bit