from the trailer, they show CARTRIDGES! But also show Splatoon on the NX. I hope they bring Sm4sh to NX too :D
also seems the NX supports the Wii Mote if i saw correctly.
Sonic 2017 is also coming to NX :] AND i hope they bring the weebish games to NX such as Madoka, Baka and Test and Re: Zero...