Grasshopper Manufacture isn't huge. The numbers they made on the Wii may not cover them for the development of a game on the HD twins. If he does move it, it will probably go to 360. Either way, I'm gonna buy it. :P
Why the 360? Why not cross platform, the 360 isnt too big in Japan, It would't make more sense to make his next game cross platform or Ps3 Exclusive NMH was originally going to be developed for the 360. The game didn't do to hot in Japan so it wouldn't be too much of an issue anyways.