Nintendo of America revealed the release date in a tweet earlier today. He's the second downloadable character in the game, after Mewtwo who was released back in April. More characters will be added to the game in the future.
I'm not sure how popular Lucas is in the world of Super Smash Bros., but I still love the idea of including a character from a game that wasn't even release in the U.S. That takes guts Nintendo.
Oddly enough, this news makes me want to play through EarthBound and Mother 3 now, which I've never done before. I know, I'm a bad person.