Whatever he does, all I ask is no more clone characters, at least when it comes to characters that shouldn't be clones. Alternative forms for a particular character is fine to clone, as long as it doesn't take too much away from developing other areas, but make every distinct character fresh and unique.
I hope they just ax subspace emissary (or some other alternative) and go back to the more simple 1 player modes of the previous games. Sadly I don't think Sakurai will let go of that idea, he seems to like cramming everything he can into a game, even if I feel it would be better to direct the vast majority of the resources to crafting characters, levels, and balance.