During a special Nintendo Direct today, Nintendo confirmed the inclusion of Mewtwo in the new Super Smash Bros.
Both games, for Nintendo 3DS and Wii U, will receive a free DLC update for the king of psychic Pokémon during Spring 2015. Nintendo confirmed that there is a fair bit of work to get the character included in the roster; given the need to ensure things are sufficiently balanced.
Mewtwo will be available as a download for those who have purchased both versions.
What other characters would you like to see added to the Super Smash Bros. line-up?