NSMB2, Rusty's, and StreetPass are not huge competitive releases of Nintendo. If they make a game where in order to have all of the available characters competitively in a tournament you have to pay 3 bucks, or if you go online and you can't play as a character because you didn't pay, or if they lock a veteran that people have played for years, or if they lock a new hyped newcomer, the backlash would be huge! Mario Golf has paid DLC, but that was purely cosmetic with maybe a slight curve of your swing, this is Smash where a new character adds a whole new element to every other character and the entire balance of the game.
I think any character DLC will be free, if there is character DLC. any paid DLC would have to be stages, events, stuff I've mentioned.
This, too.