I've mixed feelings. It looks like gaming is about to become a whole lot more personal and even more interactive, an idea I like.
However, one of the very good things about the original Wii remote is the freedom it allows. For the most part, I have used the Wii Fit, and I cannot see it being quite as efficient with a much larger remote. Same goes for some of the other more physical games, like baseball, tennis, bowling, et al. I can see them releasing a secondary, smaller remote after the console has been out for a while - perhaps an added feature to the next generation Wii U Fit.