Going by leaks so far HappySquirrel all 3 next gen consoles will have a similar architecture and, more importantly, their GPUs will have the same feature sets. I'm fully expecting the U to have no problem receiving down-ports and supplying up-ports from and to the PS4 and 720.
You'll obviously see the eye candy being downgraded but the average gamer (and it still surprises me that these days more gamers aren't clued up as far as hardware and graphical effects goes) won't see a great deal of difference between the U SKUs and PS4/720 SKUs unless they're looking at them side by side. You'll probably end up with a lower native resolution, more jaggies, more pop-in and longer loading times but the games will still look and play fine on the U.







