I don't think Wii Fit U will match sales of Wii Fit either, but I'm sure it will help move some systems. Wii Fit actually had some pretty fun stuff on it, I especially liked the obstacle course, I also like the scales and the ability to weigh my pets (which I actually do from time to time, my cat weighs 17 lbs, and my dog weighs 75). I plan on getting it for my wife, because she plays the old one quite a bit. The pedometer looks exactly like a Pokewalker made from different colored plastic, I'll have to be sure not to throw this one in the washer. It would be kind of nice to have some connectivity with the 3DS's pedometer on this.
I'm really looking forward to Lego City, it looks really good from what I've seen. I can't wait for Luigi's Mansion either, I've had it pre-ordered for a long time.