-Arcade mode
-Resigned menus - Arcade, VS (VS player, VS CPU, CPU VS CPU), Online, Challenges, Training, Games (break the car, smash the barrel) Settings, Gallery, Store.
-Characters - Akuma, Sagat, Blanka, E Honda, Fei Long, Dee Jay, T Hawk (bring the original world warriors back!), but now bring characters from SFIV, SFIII, SFEX3, and SFA3...in addition to brand new ones
-Stages - more classic and brand new stages
-Music - bring back original tracks from past games
-costumes - classic, new, bikini are all good
-Make loading screens disappear or at least be significantly reduced. I would play this game a lot more but the amount of time waiting to get a match online or if you're in between matches or sometimes just connecting to the server is painful.
-have other methods to earn FM, reduce the challenge of survival
-don't have most of the game tied to online or at least a backup of FM earned if game disconnecteds for whatever reason.
All I can think of for now.