I always thought that if you take Meta Knight out of the game, Brawl is actually balanced quite well.
SS: Meta Knight
S: Ice Climbers
A+: Olimar, Diddy Kong
A-: Marth, Snake, Falco
B: Pikachu, Zero Suit Samus, Wario
C+: Lucario, King Dedede, Toon Link
C: Wolf, Fox, Mr. Game & Watch, Pit
C-: R.O.B., Peach
D: Kirby, Donkey Kong, Sonic, Ike, Sheilda, Sheik, Ness, Yoshi
E: Luigi, Pokémon Trainer, Lucas
F: Mario, Samus, Bowser, Captain Falcon, Link, Jigglypuff, Zelda, Ganondorf
The bolded become viable if you take MK out of there, or at least nerf the shit out of him. I'd be more than satisfied with 8+ tournament viable characters in the game. It's when ONE completely and utterly dominates that kills a game for me. Also, the fact that NO ONE managed to catch this dominance during the balancing phase of Brawl that begins to scare me. Sakurai reaffirming that Smash 4 will undergo the same process as Brawl is not good news to me.
Still hoping for the best...
Is balancing 1v1 on FD really that painstaking, though? I've said this before... if you balance for that style of gameplay, with everything stripped away but the characters and their movesets, adding items, final smashes, stage hazards etc. will not unbalance the game. The same cannot be said the other way around.
Even still, I don't understand how they managed to miss how overpowered MK was. Turn every item on, play on the most hazardous of stages, in a 4 player free for all. MK is still fucked.