no way will 3d mario come so soon after a launch mario. I think they will be cognisant of spacing their franchises out. Metroid could be a suprise project already underway by Retro and Zelda has already been in the works using an already made motion-control engine developed in skyward sword (what they said ate up the bulk of its dev. time).
Also, given what worked last generation for Nintendo, 2d metroid is not out of the equation anymore. We know 2d Zelda isn't out of the equation either, but it seems that is reserved right now for 3ds as that is where the initial "'New' Legend of Zelda" clue came from.







