During the latest Nintendo Direct Broadcast, President Satoru Iwata announced that Lucas from Mother 3 will be released as downloadable character for Super Smash Bros. for Wii U and 3DS.
On top of that, the previously announced Mewtwo from Pokémon will be launched on April 15th together with a new update to the game. He will cost $3.99 on one platform or $4.99 on both. Lucas will come in June.