Depends on who gets cut from the launch roster, and what new comers we get etc. Tough call to make right now, so as of right now... (this will change as more characters get shown) but for right now i'd peg DLC as...
Isaac
Ray MK
Krystal
Black Shadow
Roy
King K. Rool
...or any highly requested character that's not an AT or playable at launch.
Isaac
Ray MK
Krystal
Black Shadow
Roy
King K. Rool
...or any highly requested character that's not an AT or playable at launch.