At Nintendo Direct last night, president and CEO Satoru Iwata let it be known that Namco Bandai are currently working on a new Super Smash Bros title.
The project is being headed up by Masahiro Sakurai, and his team are collaborating with Project Sora (of Kid Icarus: Uprising fame) instead of usual Super Smash Bros devs HAL.
Details are a little thin on the ground at this stage, but what we do know is that the game is expected on both Wii U and 3DS.