To be honest, I've been waiting for this day to come. Hahaha!
Sonic the Hedgehog
Chances: 95%
Now 95%... that's a lot don't you think? Hear me out on this. As we all know in 2005 the creator of Sonic, Yuji Naka, was a part of an interview and said that he wanted to have Sonic as a playable character in Melee, but that didn't happen due to time constraints. In 2006, Brawl's E3 trailer ended with SSB's first third party character appearing in the game with Konami's Solid Snake entering the battle. With a massive fanbase to back up Sonic to be playable in Brawl and being one of the most requested characters of all-time in the series, Sonic was confirmed to be playable in October 2007 and was a late addition to the roster. Since then in 2008 with Brawl's release, Sonic's career has picked up in gaming even after the abomination known as Sonic 06 (which I kinda like since it's so-bad-it's-good) with Sonic Unleashed (it wasn't really good, but it did show that Sega was getting themselves together). However, his ties with Nintendo has grew even stronger. In fact, Sonic appeared with his rival Mario in the Olympic Games in late 2007. Sonic also has numerous upon numerous console exclusive games on Nintendo's systems such as the Sonic Rush games, Sonic Colors, and now Sonic Lost World. As of right now, Nintendo and Sega are in a partnership which does help his chances by quite a bit in my opinion. Not only that, but Sonic Team's Takashi Iizuka said in an interview that he would like to have Sonic be playable in SSB4, however he mentioned that it's more or less Nintendo's decision for him to return. Lastly, Sonic barely has competition. His massive fan support from Brawl is still there or it's stronger by now meaning that he has an edge over most third party characters even still. Snake, the other third party character in Brawl, doesn't have as good of chances of appearing over Sonic since the Metal Gear Solid games haven't appearing on Nintendo consoles as of recent (the 3DS got a MGS3 remake while the Wii U doesn't get MGS5 for some reason) while Sonic has been active on Nintendo consoles. The one obstacle standing against Sonic is Sakurai himself as he may want to bring back Sonic or may not want to bring back Sonic at all. With all of this in mind, I think Sonic has great chances, possibly even greater chances than he had in Brawl.
Want: 100%
I have been a Sonic fan for a long time (I am a bigger Mario fan however). I love the classics, but I've been playing games like Sonic Adventure 1 and 2, Sonic 06, Sonic Colors, and the amazing Sonic Generations as of recent and I have grown to like the character even more. I would understand if Sonic didn't return, but I would be incredibly disappointed if he didn't as he just fits in so perfectly. I hope that Sonic comes back with a better moveset as well.
Genesect Prediction: 20.3%
Genesect is popular, but I don't see it having massive chances even though it recently got a movie.
Nominations: Bowser Jr. 5x
Umm... sorry for the long post. I hope you don't mind! Hahaha!