Yeah, one thing that's been made very clear, and makes a lot of sense, is that to be a Smash Bros character, at the very least a character needs to have appeared on a Nintendo console in a major release. The reason that Snake appeared was that A) Metal Gear 1, 2 and Twin Snakes were all Nintendo games, and B) Sakurai (the creator of Smash Bros) and Kojima are close friends, and specifically wanted to collaborate. Also, this is just speculation, but for non-first-party games, I would expect that they would choose games that were big enough to appear overseas... acting as the flagship characters for their series. They're not going to pick obscure characters that never made it out of Japan to act as emissaries for a non-Nintendo developed title, so I wouldn't count on Innocence being a promising pick, especially since it recently lost it's Nintendo-exclusivity in a recent remake for Vita.
For Tales games, that leaves Phantasia, Symphonia, and Abyss. Since Symphonia and Abyss are far more well known, I'd put my money on thems. Hence, Lloyd, Luke, and possibly Tear. It's hard to imagine anyone else having a serious chance.
Edit: If they do use Luke, I can totally see them doing an Ashe swapout sort of like Zelda/Sheik. We could use more characters like that anyway.
