Instant on. No more waiting for load up screens.
Remote game control; watch a friend play a game remotely and take control and help him out....
Able to play games even while they are downloading
able to try out new games, day one, from the psn store, before purchasing.....
Streaming PS4 games to the Vita / Vita as a second screen or controller
Improved Eye and Move controls and features ( facial recognition and voice commands and built in Move on the DS4 ) probably way more useful for games than anything Kinect 2.0 can dish out.
4K movie streaming service from Sony
touch pad on DS4 can support two inputs at once ( Wii U can only support one )
8 gig gddr5 ram versus 8 gig ddr3
Games, and lots of them.
Feel free to add more to the list as needed