I doubt Ps4 and Xbox 720 will be weak. Mainly because pc gaming would be so far ahead of the consoles like never before. Be the first time its been like that for me.
If the consoles are as weak as people on system wars say they will be then this will be a much different gen than before. Its always been that the consoles at launch are on par with the latest pc hardware or close. How different of a gen do you think it will be if Ps4 and Xbox 720 are weak compared to the pc?
I think that due to this the pc gaming market for dedicated gpu's will die out and become redudant. They will no longer make games that can make use of the hardware so everybody can play at high settings with integrated graphics.
There will be less and less exclusives because pc gaming has become cheaper to get into and has become a bigger player, thus it will take a bigger share from the pie. The main difference from the consoles in terms of games will be what gimmicks they can do.
Ps4 and Xbox 720 are most likely gonna be on par with current pc hardware like gtx 680 in power. Its like those end of the world predictions, when people say the consoles are gonna be weak.