If you would like a breakdown of all of the leaks from one of the leakers themselves (vaanrose):
http://i.imgur.com/5VhbSBK.jpg
Otherwise, my quick version:
Gematsu Leak - Villager, Wii Fit Trainer, Megaman, Little Mac, pokemon from X + Y, Pacman, Palutena, Mii Fighter, Chrom, Chorus Kids, Shulk
Ninka Leak - Shulk (w/ five monado modes), Dr. Mario, Dark Pit, Duck Hunt, Bowser Jr. in the Koopa Clown Car, Alph, Koopalings, 8 costumes for all characters,
Vaanrose Leak - Robin, Bowser Jr., Duck Hunt
Anonymous 4Chan Leak (posted after Ninka and Vaanrose) - Duck Hunt Dog, Bowser Jr., Shulk, Chorus Kids, Ridley, Dixie, Mewtwo
ESRB Leak - The CSS picture that we got a couple weeks ago + videos.
Then today a mod on Smashboards by the name NeoZero with a good reputation hinted at there being more characters but there is no reason to believe him beyond his reputation.
- Gematsu veered off course when Chrom was shown to not be in so Chorus Kids can't be proven to be in by it.
- All that has yet to be shown from the Ninka leak are the Koopalings, so they're very likely to be in.
- Vaanrose is entirely true.
- The Anonymous 4Chan leak has nothing exclusive to it proven yet, so it really can't be trusted.
- The ESRB leak is of course legit.
- The ESRB leaker confessed to adding on Mewtwo, Dixie, Ridley, Impa, and Mach Rider to mess with people.
Nothing with any credibility, as of right now, is hinting at more characters being revealed.
The reason there is a "final five" speculation going on is because of the blank spots shown on the character select screen in the ESRB leak.
Dixie won't be on the game
I've never met such a huge Dixie fan. There is so many awesome characters to Stan for, why Dixie? 
Dixie is pretty cool though!
