In my personal opinion, Nintendo will be the only ones to stick it out, for a few reasons... Firstly, they're stupid, or not stupid, but rather they do things the way that they want they to and my gut says they'll keep going until their money runs out, or they focus solely on handhelds. Also, they're the only console manufacturer who makes games for their system and, lastly, Satoru Iwata, the man knew what games were supposed to be. Sony have made it clear they want the Playstation to become a service rather than a console platform and Microsoft, I don't have a solid reason for their exit, other than they don't make much money and with consumers getting pissed at the Xbone, I just don't see them sticking around for much longer.
Adding to @Amstari 's comment, I'm also very suprised by how many street passes I get walking to work with my 2DS. I don't think Nintendo will be dropping handhelds or consoles for a couple more gen.