From a bit of reading on how the Wii remote works, it seems that the technology Nintendo uses is no more complicated than normal TV remote infrared, but with an additional emitter. So the "sensor bar" is not real a sensor, but a emitter with two infrared light sources setting about 30cm apart from each other, and the remote adjust itself according to these lights.
Because the two light sources have a very short distance between each other, a small movement of the remote causes the cursor on the TV to move alot (this is just my assumption).
My idea is to build my own "sensor bar", with two small light bulbs or candles :P sitting further from each other, replacing the normal sensor bar. Hopefully this will reduce movement difference between the remote and the cursor. Will update later with more details.