The PS4 needn't be an anchor and should reduce the need for ports. I hope PC will end up as lead platform to begin with. That way the PS4 should be able to near match them graphically for a couple or three years. And by them, I mean good current graphics cards, not 600 quid a pop high end units. By the time the average PC evolves beyond that point, developers should have grasped the full potential of the PS4 and will hopefully be making top notch exclusives to keep it in touch with, even if not equal to PCs.
I think it's a good thing for the PC platform overall and I think people are underestimating this new era of unified architecture. It will be interesting when it arrives for PC (next year I think I remember reading?) with the possibility for far larger RAM configurations, though development cost may then become of far greater impedance to graphical innovation.
This all depends of course on the new Xbox not being a damp squib and dragging all the other platforms down with it. Hopefully it will be powerful enough to share the workload, if not the polish.