The initial DLC will be "Color Pack 1", which will add seven new colors for every fighter. However, only people who also own the pack will be able to see the new colors you've painted on your fighter. The Color Pack 1 will be released on September 6 for $2.99 USD.
The upcoming DLC includes "a set of Music Packs(!), which add new songs. Specifically, they add…all the character themes from the first two Street Fighter III games, “New Generation” and “Second Impact”! But wait, there’s more. In addition to the Unlock Keys, Color Packs, and Music Packs, we’re also going to be offering Match Packs."
What are the Match Packs? Well, Capcom held their "semi-secret tournament" in their corporate offices, inviting 16 of the best Street Fighter III players to due it out in what they called "Fight for the Future 2011". Each Match Pack comes with an hour's worth of content with each match that they played having pro commentary by Bruce Chen. The Match Packs will show off the events of the tourney, so players who are interested in seeing how to better their game might enjoy the packs.