Over at the San Jose Mercury News, Dean Takahashi poses an interesting question: "what does the [Wii's] optical sensor do?" The more appropriate question would be: why is the optical senor necessary?
As Takahashi notes, the Wiimote's motion-sensing chip detects x-, y- and z-axis movements, along with acceleration, and then transmits the data to the console in real time via Bluetooth. Takahashi wonders why this data isn't enough to determine where the pointer is positioned on screen.
We know that there is a correlation between the optical sensor and the Wiimote's pointer because games that don't utilize pointing functionality aren't limited by the sensor's range. But couldn't Nintendo have developed the technology to exclude the optical sensor altogether?