I
know what that setting does, I clearly meant in-game settings there, for stuff like the actual speed with which the cursor moves. If the aiming was like a lightgun then you'd have no control over that, the sensitivity would always be, well, 1:1, with no real control whatsoever over it.
Edit: Ops, nevermind, you misunderstood what setting I talked about. I was actually not talking about sensitivity at all in that particular instance.
As for the adjustable sensor bar, meh, I merely said that in the actual Wii settings you can set the size of the sensor bar relative to the TV. I did say I have no idea what it uses that data for, and if it affects cursor movement or not, but the setting is there anyway. It's just an observation.
Edit: On closer inspection that setting is NOT there. At least, I can't find it now. Perhaps it's in some game's settings, maybe Twilight Princess.
In theory, any given software could use that particular setting to determine the exact width of the TV and adjust cursor movement accordingly. If they don't, well, I guess they don't find it so necessary, or prefer having their own different options for the pointer movement and sensitivity.