I support them adding classic costumes to appease our nostalgia but they should focus on adding new characters rather than shining up the rotten apples from 15 years ago. The best characters from the series already made the cut and are in the game.
I'd rather NRS be serious about supporting this game instead of dropping it after six months for a new version.
And, the best way to do this is to invest in some new characters. Give us their story. I'd pay a premium $15 for a couple of new characters with story mode chapters added. I'm sure you would, too.
This game's engine is pretty legit and fun to play. If they really push the branching storyline, they could find reason for a whole new bunch of people to show up. Work towards setting up the next game. Maybe someone Motaro killed in the other timeline, for example. A new hero. A new villain. Someone from Europe finally? It'd be great if they really got creative with the thing, rather than finally put in a construction worker to complete the Village People cast they've been adding since MK3 (Nightwolf, Stryker, Hsu Hao...)
Or, they could make some satirical characters. Find time to create a joke character. Someone that pokes fun of action heroes of today, like Johnny Cage did. Or superheroes. Or other fighting game characters. Put some Mileena teeth on the humor! The game needs more tongue in cheek. NRS can develop better jokes and more memorable characters than Purple Rain!