*** Mewtwo ***
The only character to be planned for all three games and miss two of them due to time, as far as we know anyway. Also overwhelmingly popular, kind of a dying breed by this point.
*** Lucario ***
He's been well-received, I think Sakurai would prefer to have him stay.
*** Jiggs ***
Sure, why not. Now whar's me toothpick?
*** Pokemon Trainer ***
Lots of people suggest changing either the Trainer, the Pokemon, or both. I can't recall a time when someone suggested this without the claim that we need more stuff from anything other than the first generation. I also can't recall a more shallow argument for such a significant change, but maybe I've been ignoring ****** City* for too long. Who knows.
*** 5th Gen Pokemon ***
The only reason I don't have one listed is because I'm not seeing any strong standouts compared to any Brawl characters or Mewtwo. Try to imagine a scenario where Sakurai feels it'd be better to simply bring back those guys and focus on other series. That's what I'm leaning toward, though it's also probably the most likely prediction I'm making about Smash that I'd be wrong about. Meh.
As for which ones... well sorry, I don't care. I'm guessing Sakurai will ask TPC for an idea if he's interested. Actually, something that isn't large and ferocious or small and cute would be nice. More Ivysaurs, yeah.
**** Everything Else ****
Another Trainer: I'd like to think people here realize why a second individual trainer (more or less the same as Red) would be a bad idea. Now a female PT alt costume, THAT'S a keeper.
Previous Gen Pokemon: No indication of interest from Sakurai or TPC, and who would they pick anyway? Your personal favorite, right?
6+ Gen Pokemon: Betting all of my hair in a beautiful Toise wig on the roster being decided well before a new generation shows up.
Pichu: I like him as an alt costume (and yes, he DOES fit). No sign of interest in bringing him back for Brawl, so I'm more than willing to bet against him showing up.
Plusle & Minun: a-hyuck