I have to agree as far as the smartest post so far.
I was thinking about this over the weekend as I heard about all of these wonderful (planned/hoped-for) things in watches. They talked about joggers using heart rate monitors, etc. I was thinking that a simple blue tooth connection to the phone/hand device to send whatever telemetry. Let that device do the heavy lifting, then as GP said, send back whatever to the display as desired.
It really seems silly on so many levels to try to pack all of that into one little device on your wrist. If God had wanted us all to have Dick Tracy watches on our wrists, he would have made us all the size of the Hulk. Or something.