there are some rumors..
The Translator Leak (1/10/14)
Rosalina is the only Mario newcomer.
Waluigi and Toad were at once considered, but Waluigi remains an Assist Trophy, and Toad a move for Peach. Toad is a playable.
Bowser Junior, Paper Mario and Daisy were never Been Playable in Brawl but confirmed in rumble and universe
Fawful is a new Mario Assist Trophy. He acts like Mr. Resetti, but will attack opponents at random.
Diddy Kong will be the next revealed veteran, to coincide with Tropical Freeze’s release date.
Diddy is paired with Dixie Kong as a tag-team, similar to Zelda and Sheik. Dixie has a separate moveset from Diddy, but it’s still being worked on.
King K. Rool is a newcomer, the heaviest character on the roster. He is powerful and can KO light characters with 2 good Smash Attacks. His final smash has him use the blunderbuss and fire cannonballs from the top of the screen while they fly in from the sides as well.
Gangplank Galleon is a stage.
There is a new Zelda character, although it’s kept a secret so far. The names heard most often are Tingle and Ghirahim.
Ganondorf will be buffed, although he still retains some of C. Falcon’s moves. He can equip a sword using his Down Special.
Chrom is a Fire Emblem necomer. He wields the Falchion, and does not replace Ike.
Chrom is expected to be revealed to celebrate the anniversary of the first Fire Emblem.
Lyn’s Assist Trophy from Brawl has been scrapped.
King Gangrel and Aversa are the new Fire Emblem Assist Trophy. Gangrel runs around slicing with his sword, while Aversa flies above using Aversa’s Night.
They are the “unexpected” Assist Trophy.
No newcomers for Yoshi or Wario.
Wario’s overalls are now his default attire.
The Kat & Ana Assist Trophy has been scrapped.
Ashley from WarioWare is a new Assist Trophy.
Ridley is a newcomer, and is scaled down a bit. It was a major feat on the development team.
new Star Fox characters.
Falco is farther away from being a Fox clone.
Wolf is no longer a semi-clone.
Villager has a female costume.
Mr. Resetti Is playable
Tom Nook is a new Assist Trophy.He apparently drops bells across the stage, which causes opponents to trip. (Due to Sakurai saying tripping is removed, it’s unknown if forced tripping, like this and Diddy’s bananas will return, or if only accidental tripping is removed.)
Palutena is a newcomer, with her moves based directly off Uprising.
Magnus is a new Assist Trophy, and acts similarly to Little Mac in Brawl.
All Pokemon veterans from Brawl return.
Mewtwo and Lucario have very different movesets.
No new Kirby characters.
Meta Knight will be revealed sometime in the summer of 2014.
No changes made to the EarthBound series.
All misc. characters return(Mr. Game & Watch, R.O.B., Ice Climbers)
Little Mac is a newcomer. He has the look from the Punch-Out!! reboot for the Wii.
The Male Wii Fit Trainer is indeed an alt. for Wii Fit Trainer.
Wii Fit Trainer has a butt attack. It is replaced by a headbutt for the male costume.
King Hippo is an Newcomer
The Ghosts from Luigi’s Mansion are an Assist Trophy.
Pac-Man will be the final newcomer. He is a secret character.