The fact that Sakurai keeps talking about Ness half the time Lucas is around gives a shred of hope that he will return...but by saying "up until now"...that pretty much means he was in Smash until now...which means he is no longer in Smash.
I'm quite certain he will be an alternate costume of Lucas though, considering the wide variety of costumes and color schemes already seen with the Wolf outfit, Dark Link, Fusion Samus, etc. And the moveset is very similar to Ness....in fact if Ness was still in the game, he'd probably have this exact moveset...so really, no big deal.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )