That would lead to a too expansive system imho.
A RV740 is around 4 times more powerful than the xenos in peak figure and it is likely more efficient at his job on top of that. Both Sony and MS are likely to have more powerful parts than that thus I believe the Wow factor will be there for console users. Consoles can't compete against high end Pc especially now power consumption for multi gpu card is too high.
Even what people consider high end PC doesn't have the wow factor to sell it self. Only small number of people can justified the cost for the improvement. Graphic gimmick worked once, but Moore's Law can't make it work anymore.
Even with the system I stated, which would give greater than 30 times speed up compare to current gen of consoles, I don't think enough gamers will be impressed with it's graphic to justify it's price tag.
So unless a console maker can find a way to really wow gamers with graphic gimmick compare to their competitors, it's not a worthwhile gimmick to pursue as selling point for the console they're creating. It'll just be like high end PC, expensive with only small number of gamers that'll appreciate the improvement in fidelity over competitors.
I think gamers’ convenience is a better gimmick compare to graphic.