Basically the same time we were announced that there would be a new Smash Bros so was the head developer Sakurai. So don't expect anything real for atleast 2 years. This is a huge money maker for Nintendo, they won't release it til its right, plus its being developed for two systems for full compatibility this will make development take longer.
Despite Nintendo president Satoru Iwata's E3 announcement that the series would be hitting the 3DS and Wii U systems, Project Sora (the independent developer Sakurai heads) is so busy working on Kid Icarus: Uprising that they haven't even started thinking about Smash Bros. yet.
Yeah, Iwata sort of jumped the gun in announcing it (Maybe he was desperate to secure a killer app for Wii U), Actually, Sakurai isn't even quite done with Kid Icarus yet, so we won't see Smash Bros for at least 3 years.
At the keynote, Iwata said that they were discussing possibilities for Smash Bros for the two systems, and that they had ideas that would one day become a game, but no development has started. Therefore, there's no news on the game other than the fact that they may start putting the team together to start working on it in the future.