Eh, IF they do it, expect something more along the lines of Animal Crossing than Zelda Online.
Frankly, I just don't see it happening... Nintendo is still using friend codes and while the newest Mario Kart is a step in the right direction, its communication options are still WAY to limited for a functional MMO.
Sony already has a studio dedicated to MMO/online game development. Granted they don't exactly have an awesome track record, but they DO have experience in the MMO market, which Nintendo doesn't.







