All new console launches have previous gen ports, some untouched and some enhanced.
The U is going to have the definitive versions of several titles - Black Ops 2, Ninja Gaiden 3, Darksiders 2, Assassins Creed 3, Arkham City, Sonic All Stars Racing Transformed, Tekken Tag Tournament 2, Trine 2, Just Dance 4 and Aliens Colonial Marines. Some of those are late ports but they are all an improvement on their PS3/360 counterparts in one way or another whether it's improved graphics, DLC included, extra content or improved gameplay.
It also has some stellar exclusives - NSMB U, ZombiU, Rayman Legends, Pikmin 3, Lego City Undercover, Wii Fit U, Scribblenaughts Unlimited, Monster Hunter 3G Ultimate, Sing Party, The Wonderful 101, Nano Assault Neo and Little Inferno.
I've never seen a better console launch in all my years of gaming, and I've been gaming since the 70s. Certainly pisses all over the 360 and PS3 launches.