The youth with the psychic powers has appeared—it’s Lucas! He makes his anticipated debut from the Japan-only release MOTHER 3.
While he is timid in nature, he fights splendidly. Is it possible he can surpass even Ness?!
http://www.smashbros.com/en_us/characters/lucas.html
This may mean that Ness is out. Ness was supposed to be replaced with Lucas in Smash Bros. Melee, but since Mother 3 was about 5 years away, they kept Ness in.