Soundwave on 11 September 2014
It has to come out because they can't launch amiibo without it and having a toy launch that misses the holiday season is even worse than a big game missing the holiday season.
They will ship the game no matter what come late November, even if some characters/stages are incomplete as a worst case scenario they can add them in later as free DLC.
The reason they're focusing on the 3DS Smash now is because it's coming out first (obviously). Nintendo does this fairly consistently, for example we saw nothing of Yoshi's Wooly World until Yoshi's New Island (3DS) came out first. Once it released, then we got (finally) a new look at Yoshi's Wooly World.
