I don't think PS4 or XB3 are going to struggle.
This is strange transition, because even though the Vita is very much a traditional generation leap, within the context of a handheld system, it's kind of a meaningless jump because of it's lack of support, and both the Nintendo systems have no sense of progression about them. 3D is a kind of cool gimmick, but the world doesn't care about it, and performance wise the system isn't impressive. The Wii U has the tablet, which is only impressive to anyone who's never used an iPad, and system wise isn't producing anything of technical note so far.
All three are just not interesting, and certainly not exciting. I think the next PlayStation and Xbox will be different, because they'll come with the new announcements of all the games we're going to be playing for the next couple of years. Even if the consoles themselves aren't doing anything interesting, and barely keeping pace with PCs, it'll be a turning point for the games, that's what matters.
If those two tank, I'm not sure how I'll feel about it. Sony make a couple of games I like, only a couple though, MS make nothing I care about. I don't really care that much about either platform from a first party perspective. The third party games matter, but I think given the x86 architectures, the popularity of Steam, and the 'struggle' of transition, everything is going to be on PC, so even if both consoles fell completely flat, and I don't think they will, I'd just focus on PC, which although I don't like as much, I have no issue with.