If the vitality censor was a wrist band rather than a finger splint, then it would be much more applicable. It could read your pulse from your wrist while your hand is still occupied with the nunchuk (meaning the vitality censor would need a redesign so that after plugging it in, you could then plug the nunchuk in to the end of it also, effectively using three peripherals. Nintendo wants to incorporate the player into the game as much as possible, and if they could deliver an awesome Wiimotion+ experience using the Wiimote and the nunchuk and incorporate your heart rate into the difficultly using the vitality censor, then by gollie that would be the best game of all time. It would truly be playing Zelda like never before.
Currently, your active heart in your health bar is enlarged and beats when you're close to dying. If it would beat faster in correspondence to your actual heart beat, that would be amazing on too many levels. You could read your level of fear, anxiety, and passiveness from simply looking at your hearts. It would give them a whole new meaning, thus tying the player to staying alive more, because if those hearts are beating and dwindling to nothing, then psychologically, you might feel that YOU are close to dying, which would motivate you to stay alive in an otherwise really difficult game. It could be the best gaming experience of all time.