Well I could be wrong but I expect PS4 & XB1 games still have a long way to go technically.
1) Launch games are developed in a very time crunched situation with tools not being great, SDK's not being stable, etc. so I think just from having more time, and the maturity of tools games will get much better than you can see today.
2) Current games haven't even begun to use GPU compute.
3) Current game tech on PS4 & XB1 has been ported from PC, but PCs have very inefficient GPU drivers compared to the low level access on PS4/X1. You can see in AMD's Mantle SDK how they're able to increase draw calls by 900% compared to D3D. What you see done today on PC on equivalent GPUs is not the limit for PS4/X1.
Look at this: http://cdn4.wccftech.com/wp-content/uploads/2013/12/MantleBenefits1.jpg
Yes, PC games will "leverage optimization work from next gen game consoles".