Unfortunately, no.
From the Star Fox series, Wolf is the only addition to the group in Brawl, Fox and Falco stay in.
I'm told there are some characters that can be unlocked through a series of cheats...however, I have yet to confirm this, and know not who these "hidden characters" are, or whether they work or not.
krystal is not a playable character in brawl
No, Jack Skellington is not a playable character in Super Smash Bros. Brawl.
Sandbag is not a playable character on Super Smash Bros. Brawl, it was made to be more of a punching bag.
He is not a playable character, but if you have Homebrew, you can control him on Boss Battles ONLY
No, but he does have an appearance in the storyline and is the final boss in Classic mode.Taboo is not an unlockable character in Super Smash Bros. Brawl.
krystal is not a playable character in brawl
She is, but not as a playable character.
No, Jack Skellington is not a playable character in Super Smash Bros. Brawl.
No. Tom Nook is not a playable character in Brawl.
No. Naruto is not a playable character.
No, Pichu is not a playable character in Super Smash Bros Brawl
No
Midna is not a playable character in Super Smash Bros Brawl
WALL-E is not a playable character in Super Smash Bros. Brawl. You are most likely referring to R.O.B.
No he is not a playable character.
He is not a playable character.
Lucario did become a playable character in Brawl.