When I first heard that Sakurai would be dropping characters in Brawl by stating that "not all characters from Melee will return", I really started to worry about the fates of such characters as Ness, Mewtwo, Ice Climbers, Mr. Game & Watch, and other obscure characters.
My predictions for returning combatants:
Luigi (95%) - The only reason he isn't 100% is because he hasn't been revealed yet lol. I think it's pretty safe to assume he'll be there, probably with a reworked fighting style to further differentiate him from his brother. I also think he'll be a secret character again... and may play a surprising role in the Subspace Emissary...
Captain Falcon (85%) - Although he could be considered obscure in that he never really leaves the cockpit in his own game series, and not necessarily being from the most popular of Nintendo's franchises, he has appeared in both the original Smash Bros and its sequel. On top of that, his rival Samurai Goroh (Though unfortunately not playable), has been confirmed to be in the game.
Ganondorf (80%) - His presence in Melee was well deserved, but strangely as a clone of Captain Falcon. Most people believe that the villain will return in Brawl with an all-new moveset and his appearance taken from Twilight Princess, as with Link and Zelda. If he's not revealed as a veteran before the game's release, I'd expect him to be an unlockable character.
Shiek (70%) - Although we already have Zelda confirmed, we have yet to see her alter ego. It's possible she may have been dropped due to the character's appearance being taken from Twilight Princess (Where Shiek had no role). However, Zelda's fighting style looks unchanged from Melee, so it's possible she may still have this transformation... and there's always those rumors...
Jigglypuff (65%) - Notable for being a popular character in Japan (And to a lesser extent, in the US as well). Jiggly was probably the first unlockable character most players would discover when playing through the games. That may be true once again just for old time's sake, but Jigglypuff's popularity has seemingly dropped since the revelation of new pokemon such as Lucario, Blaziken, and ugh... Gardevoir.
Falco (65%) - The Starfox series hasn't really been able to hang up there with Mario, Zelda, and Metroid lately, but to the Starfox fanbase, Falco remains a popular character and fan-favourite. Although a clone of Fox, he remains a requested character to return, though I believe he may be replaced by Krystal.
Marth (60%) - Marth has not been featured in a Fire Emblem game in years, and is notable for being the primary protagonist of the very first game. Since Ike's unveiling, I believe Marth's chances of being in are slimmer than before. And if by chance, another Fire Emblem character from the most recent games makes the cut, I'm sure he's gotten the axe.
Young Link (60%) - Although a fairly popular character from Melee, (And even stated to be the "True Link" in his trphy description), his chances are looking slim... at least in his previous incarnation. There's rumors abound about Cel-Shaded Link filling in for this clone, but I still think this is unlikely.
Mewtwo (55%) - Even three generations of pokemon later, Mewtwo is still one of the only Pokemon to be considered a villain (Deoxys is out of the picture). Unfortunately, Pokemon isn't generally known for evil villains, and Sakurai might deem Mewtwo inadequate for that reason, as well as the fact that he isn't nearly as popular anymore as he used to be. It doesn't help that he was considered one of the weakest characters in Melee (A contrast to his stance in the pokemon games and anime). Many tend to think that he might be replaced by Lucario, though it isn't impossible for them to coexist. Plus, most legendary Pokemon have receieved some sort of acknowledgment in Smash, and I think Mewtwo would too. It's even more unlikely he'll be a pokeball than get the boot.
Ness (50%) - Poor Ness. He was originally planned to be the only character in Melee to get the cut and be replaced by Lucas. This didn't happen since Mother 3 hadn't been released yet, and Ness barely made it. This time though, Lucas is here, and no word of Ness other than the possibility of him "surpassing Ness". Although I think he may be in there, possibly as an unlockable to throw off fans, to fight alongside Lucas... unless another Mother 3 character makes it in.
Mr. Game & Watch (50%) - The rumors of him being cut along with Ice Climbers were proven false (The ICe Climbers are confirmed)... but nothing has been said about G&W. He was definitely one of the most unique characters from Melee.
Roy (30%) - Roy was the protagonist of the Gameboy Advance Fire Emblem, and has not appeared in any recent game (To my knowledge). He might get the cut for very much the same reason as Marth... But doesn't have any real reason to return other than to be another veteran.
Pichu (25%) - Really only a joke character form Melee. Was Pikachu but lighter and did damage to itself... I don't see it returning unless to provide the same role.
Phew...
Firsts posts are always a doozy