I was under the impression that the bands would only "work" in the Mario and Co. part of the landI think each area and attraction is interactive in different ways. Yoshi is interactive in a passive way that doesn't really affect the actual experience. Mario Kart is all about winning. I believe Donkey Kong is interactive in that there will be AA characters to talk to in the land and the queue (and they talk back,) but not sure yet how that translates to the ride experience, but I bet it has something to do with it.
I'm not sure why I was thinking that, but if there is stuff in the DK area that's very interesting