Well yeah, I guess technically you'd have to recalibrate if you use the controller from a different position. It could be implemented really simply at least: press the home button, tap the immediately accessible recalibration icon, hold the controller up toward the TV, it counts down from 3 and sets it (very nintendo-y), then press home to return to your game. When you first turn the system on it would ask you to do this right off the bat to get you used to it, and then make the icon flash and be like "THIS IS WHERE THE ICON IS DURRR". You'd only have to do this once from your current position. If you play from the same seat every time, you wouldn't ever have to recalibrate at all. Positions only slightly off wouldn't really need recalibration either unless you're super OCD (like me, lulz).
It doesn't seem like it's doing its job though. Watching the reticule gradually drift while people were flinging shuriken in Takamaru's Ninja Castle was really irritating (and depressing). Maybe Nintendo just hasn't taken advantage of it yet, but I dunno...
I've actually been pretty optimistic about Wii U, but this one little thing is really bugging me for some reason.