Super Smash Bros. will be released first on the 3DS
As part of Nintendo Direct pm on April 8, 2014, the director of Super Smash Bros. , Masahiro Sakurai revealed the departure time of both versions of the game, and surprised us by saying that the 3DS version will come out in mid- year and the Wii U at the end of it.
Sakurai also stated that the 3DS version will run at 60fps even in 3D. Some trophies attendees will move to 30 fps, but all the fighters will move to maximum frames.
The games have the same roster, which means that all the playable characters will be revealed before the release of Wii U. As for music, apparently the 3DS version presented by stage 2 Songs out. Finally, both versions will interact.