Ubisoft's Your Shape mainly uses a camera, and EA's series looks to be focusing on cheaper exercise equipment like the resistance bands in the first game. I know EA's Fitness at least supports the balance board, but I'm pretty sure it doesn't require it, and I don't even see mention of it on the Your Shape website.
As for NSMBW, the reason there are not more successful 2D platformers for home systems out there is because there hasn't been a 2D Mario, Donkey Kong or Sonic game for a home system since DKC3 in 1996, and no company has attempted to launch a new 2D platform "mascot" character since the 16-bit era. The industry are lemmings, and they just followed Super Mario 64 and the early Crash Bandicoot games, and when nothing could recapture the explosive success and excitement around those games, platformers just dwindled. No one turned back towards 2D until, well, NSMBW.
I think there is a market for 2D platformers who have gone unserved since the mid-90s. The only 2D platformers even out there for home consoles are treated like niche games, not like "mascot" games like they used to be.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.
