The psychic Pokemon's demise was greatly exaggerated.
Buying both the 3DS and Wii U versions of Smash Bros. will give players the chance to play as Mewtwo, who was retired from the Smash series until now. Mewtwo will be available as a free download after registering both versions online.
The Mewtwo promotion is set for Spring 2015 and will allow Mewtwo to be playable on both versions come release time.