XBox: So really, what will keep them afloat? They're rich. Simple as that.
PS4: That's a hard one to call. Face it, it can't go face to face with Microsoft again in that red ocean, let alone with Nintendo putting their names in the hat as well. It wasn't like the last generation where it was a two man race. For Sony, they have to set themselves apart completely. COMPLETELY. With the recent junk status of their credit and their TV division not doing too well, it has to be completely different. It will survive, but it can't fight the same war.
Wii U: It seems like Nintendo is finally stepping up their game. Nintendo Directs with their leader playing a character of his own. Merging departments, getting third partys into the mix(Bayonetta, SMT X FE, welcoming indie devs, etc. Getting into an HD model. Expanding their Mii into a Miiverse social network, which to me is a really good idea. RIght now it's a little be of a mess, but it can get really big if the right game were to be incorporated. A little late to the party, but they don't need much to survive.
Unless Sony and Microsoft come up with a very innovative new console, it's a 3 man race in this bloody ocean of an industry. Despite this, I do think that all 3 console makers will make it out alive this console cycle. Why, because there's nothing taking away from console sells. You can say phones and tablets, but right now those devices aren't sophisticated enough to take away legions of fans away from the big 3. Also, the phone and tablet infrastructure can't compete with the dedicated gaming machine infrastructure. Maybe if 3 of the biggest phone giants put in for a 3 year time period, maybe. Maybe....