I actually wouldn't be surprised to see it built into the controller, sort of like how on exercise bikes they have built-in heart rate monitors that connect through your bare palms. Maybe it would be built into the bottom of the controller and it would react to your pulse?
The idea is legit. Why not have a game react to your real-life anxiety, stress, or relaxation?
Definitely needs to built into the controller. These sort of devices have failed in the past because they are gimmicky and awkward to wear. Integrating the sensor into the controller allows for added functionality. Also if Nintendo is returning to a more traditional controller design, I can see something like this being easily implementable. They just need to make sure that the sensor is somehow always in contact with the hand.
It's coming with Wii 2 or Wii HD...lol
Dear Gaming Gods please kill off this stupid vitlity sensor crap, or if you can't please make it not suck!
Why Nintendo? you were on a role! Why this crap?