Capcom apparently lifted the DLC release date curtain for Japanese owners of Super Street Fighter 4 interested in costume packs. Eventhubs has obtained a fairly complete release date schedule for this version of the fighter, and like them, we'll go ahead and assume the prices and release dates won't be too far off from their inevitable US releases.
Note that the Super Classic Pack is already a thing for people who pre-ordered the game. Those lucky dogs are already sporting cute new duds for Guile, Blanka, Gen and Fei "I loooooooost" Long.
Release schedule for Super Street Fighter 4 alt. costumes [Eventhubs, via MTV Multiplayer]