[Update: Greninja and Charizard have also been confirmed as fully playable characters.]
Nintendo has given Pokemon a major focus in the new Smash Bros. games heading to the 3DS and Wii U this year, as Master Balls are entering the mix. They basically function as the same old Pokeball items you know and love in the old games, but only summon legendary Pokemon.
Confirmed Pocket Monsters include Meowth, Electrode, Eevee, Staryu, Metagross, Fennekin, Meloetta, Gogoat, Entei, Deoxys, Palkia, Kyurem, Victini, Keldeo, Xerneas. Mega Lucario was also shown, which is most likely his Final Smash. I'm totally okay with this!