Since nintendo just gave their plan for e3, IT'S PREDICTION TIME!!!
At least one trailer announcing at least one newcomer. This is my expectation and it would be very surprising that it doesn't happen.
For veterans, a lot of choice so hight possibility of seeing multiple one but at least one and I think it will be mew two (at least one is expectation, mew two and more is speculation).
Now this is what I expect what I hope and is possible is:
Newcomer
(one or all of the first 2 announced would make my day)
Paper mario (no biais here the James Anderson leak has a hight chance to talk about a paper mario game but if it's the case, the game would have been in development for at least a year and a half. Imagine how fitting it would be to announce the game + characters and all rep at the same time. btw, the Rosalina trailer was a merge between ssb4 and mk8 I think it could happen there.)
Ridley (if he ever does that, Sakurai is the best troll EVER)
Palutena (why she hasn't been announced already?)
Chrom
Veteran
(at least 2 of them because really, we need more veteran announcement)
Wario (same as palutena)
Captain falcon (hype enough for e3)
Ness (this one I'm wondering why he was not announced)
Ganondorf (please declone him)
ice climbers
Expected new info
More on customization (this one is a given)
Connectivity between systems (same)
new adventure mode on wiiu (melee please)
Outside of smash
Zelda wiiu (a trailer with reveal of ganondorf would be fitting)
paper mario game (said why earlier)
new metroid prime like by retro (I wish…)
My minimum to be happy is one newcomer (which will happen).