Shigesato Itoi (creator of Mother series) has recently said this in japanese magazine, Nintendo Dream, during an interview:
If someone were to tell me they'd like to make a Mother 4, I might just say, 'Go right ahead!' (laugh) Yeah, I'd love to play a Mother 4 if there was one.
He has said in his blog that he will not create a Mother 4, so perhaps we will see the fourth title being made for the Wii or DS, by someother person. I'd prefer Mother 4 to be a 3D Wii game, as that would invite more exposure to people that prefer playing 3D games.
Besides, I think the Mother series has seen enough sprite games. It's time to move on, IMO.
What do you think?
EDIT: Forgot to mention, that Itoi could simply oversee production of Mother 4, or just criticize the pros and cons about the game....offering guidance. Not spending an overwhelming amount of time.