Despite not being directly involved, Miyamoto says he can see some potential in the device. Is it a game controller though? Even Miyamoto isn't quite sure.
It's just what the Wii didn't need... a gimmick. I know others have been critical of some of the things on the wii as gimmicks before, but this is the Powerglove for the Wii, except way less cool.
While I wasn't overly impressed with Nintendo's press conference (I'd much rather have had 2-d Metroid than New Super Mario Bothers Wii and other things like that) I did appreciate the effort this time around. While I was more excited about things coming for the 360 (I own a 360 and Wii... and every other Nintendo console) I did enjoy watching Nintendo actually try.
The vitality sensor made me cry though. It just confirmed that Nintendo is targeting dollars and not gamers. I mean, to a degree, when you get to where some developers are, they actually care about the product they make and not so much about money. Miyamoto is a great example. I think a lot of his ideas are what have made the Wii successful and he really wanted people to enjoy it. Whoever made the vitality sensor probably wants people to enjoy it but sees it more as a way to capitalize off of Wii Fit+.