Personally, as I've stated with so much excitement, I feel the leak is beyond legit. It's a gut feeling I've had since I've first laid eyes on it. I feel that due to the fact that most people know of it, those characters will surely be announced. If I'm wrong, then that's all fine. All I can say is that we can expect some surprises, and if there's nothing more, we should surely be glad for whatever we get from here on out.
I personally wish for Rayman, even if others feel that'd be off. Even if he isn't a classic, he's become that definition to me growing up. I understand that he's a 3rd party character, but it'd be amazing to me to see a match such as Rayman against Sonic or Mario or Diddy Kong. As the same with you, I also hope for Impa, Isaac(DEFINATELY or at least one character from the Golden Sun series -- I mean, Nintendo owns that brand officially beyond the official, yes?) Mach Rider, Dixie and King K Rool.. Again though, I'd still be happy with whatever was given, and if there's more to come in the future, that'd be a bonus even if I have to shell out some money[personal problems completely asside over this particular title]