Despite seeing Super Smash Bros. extend across Nintendo 3DS and Wii U, Sora Ltd.’s Masahiro Sakurai had stated in an interview that there will no be cross-platform play between the two versions. When asked about this decision, Sakurai explains they each version has completely different stages, and that cross-platforming would not work.
Super Smash Bros. on Wii U and 3DS will still have some kind of interaction with each other, however; as players can transfer customized characters from the 3DS version over to the Wii U version. Sakurai did not specify what the character customization will be, but he said they won’t be different costumes or items that players have to unlock through repetitive play-throughs. Sakurai believes different costumes take uniqueness away from the characters.
Sakurai’s goal for Smash Bros. is to make sure that the interaction between the two versions is easy and stress-free, and that the overall experience is not boring or repetitive. When he was asked if the next Smash Bros. will have a level editor, Sakurai left no comment on the subject.
This is disappointing news for people who wanted to play the same matches with each other using different versions. Hopefully when they are released, they will play differently enough to have their own identities, and that people will enjoy them.
SOURCE (http://www NULL.joystiq NULL.com/2013/06/13/wii-u-and-3ds-smash-bros-will-not-have-cross-platform-play-wil/)