Nintendo won't leave. They just...won't. Even if the WiiU bombs (which it won't), the success of the 3DS will carry them through.
MS could easily leave next-gen, but they'll move more to casual, to promote connectivity with phones etc., so they'll stay.
Sony is most likely to leave, but they won't. They can't afford to have another PS3 or Vita. They have to have a good priced, underpowered console. But why not get a Ninty or MS system, if you don't care for exclusives?
I see, if any go, it'll be Sony to 3rd party.







