Wolf
Want: 100%
Chance: 100%
Wolf has always been top 3 among popularity and currently the most likely to return in chance. He currently is the combined overall most likely and popular character compared to other characters within top 3 of both lists. Snake is unlikely due to Konami and K.Rool's chances aren't as high as people think they are confusing that with popularity (Smash Ballot is not a popularity contest or vote).
He is a veteran from the previous game, so far DLC has heavily been in favour of Veterans, due to the fact they already have some assets (Animations, Art, Sounds etc.) already existing he would have an incredibly quick turnaround time for development.
Wolf represents for the Star Fox series what Fox and Falco do not, an Anti-Hero, a Villian and a Rival.
The most likely reason that he was cut, was that he actually wasn't cut just that others got higher development priority and to not spoil the new look early to coincide with the new game. With the upcoming Star Fox Zer game being a reimagining of the Original 64 game, Wolf would most likely be based off his look in that game instead of his Assault/GameCube Era Skin (Although that could be a alternative skin for him. You could argue Fox looks the same in Brawl as he does in Smash 4 so why would things be different for Wolf? If you actually had played any of the Star Fox games you would notice that Fox in Brawl and Smash4 look nothing like any of the games he has actually been in. It's very coincidental that his representation in the last 2 smash games actually resemble the upcoming new Star Fox Zero game the most given he looks nothing like the other SF games he has been in.
The new Star Fox Zero also gives a good opportunity to cross promote. A possible pre-order SFZ and get Wolf in Smash DLC for free and early similar to Mewtwo would be a opportunity for Nintendo not only to introduce the Star Fox series to a new generation but also boost sales of both games.
The "He is a clone" is nonsense argument for why he was cut and is based on complete ignorance from a casual observer. The developers have stated which characters are Clones and Wolf is not on that list. When you compared his moveset and properties they are also completely different (
http://www.ssbwiki.com/User:Toomai/Cloneosity).
At the moment we are likely to get 4 more DLC characters. The chance of Wolf not having one of the slots is completely ludicrous beyond belief.