Nintendo Okie says, "Last year, Nintendo showed a picture of the Wii Vitality Sensor and Iwata briefly talked about the possibilities of it helping people to relax and even fall asleep.
While that does not sound super exciting to me, I am currently watching the Ubisoft Press Conference(while typing this!), and they just showed what appears to be their version of a Wii Vitality Sensor.
They even demoed the unit with software, that had the host trying to breath in-and-out, according to which way a bubble was moving up-and-down in a curved line.
Here’s a picture of both of them, side by side:"