Changed my vision a bit from recent opinions...
I think there will be 5 lines of 9 character slots this time seeing how the rules of 4 slots max have been broken with Rosalina... 44 characters and 1 random icon.
Pretty much confirmed:

Is coming back since Sakurai talked about balancing the falcon punch in an interview.

Seen on concept art and Ashley and Waluigi have a W sign in the direct.

Seen in concept art and the halberd is back.

Also on the concept art Sakurai showed.
good chance:

While the ice bears are seen in Smash Run there's still a small chance 3DS couldn't handle them.

Needs a new moveset but he's never going to be cut for Ghirahim, like Bowser would be replaced for Petey Piranha right?!

Probably coming back.

Original 12...

Original 12...
Danger Zone:

Unfortunately Chrom might take his moveset but a bit faster but they could add Robin and keep Ike aswell.

Only one of them will return, Ness has the most chance but you never know.

/

Only one can return with an airwing/wolfen and some changes too play different enough from

Pokemon might get 6 slots but if they get 5 his chances are small to beat
Probaly Cut:


Pokemontrainer is gone and people prefer either

/

over them.

Seeing

use grenades and items overall from his moves and the developer himself semi-deconfirming him....