No. Tom Nook is not a playable character in Brawl.
No, Jack Skellington is not a playable character in Super Smash Bros. Brawl.
No, Pichu is not a playable character in Super Smash Bros Brawl
Midna is not a playable character in Super Smash Bros Brawl
No. Naruto is not a playable character.
WALL-E is not a playable character in Super Smash Bros. Brawl. You are most likely referring to R.O.B.
She is, but not as a playable character.
No he is not a playable character.
He is not a playable character.
There is not playable character called Jet in Super Smash Bros Brawl.
Groudon is in Super Smash Bros. Brawl as a Poke Ballsummon, but not as a playable character.
Lucario did become a playable character in Brawl.
krystal is not a playable character in brawl