After word leaked out earlier this week that DLC would be available adding more characters to the game shortly after launch, Capcom set the record straight today by posting a press release to their development blog detailing the DLC.
The Championship Mode pack will be available as a FREE download postlaunch. Since the game's not out yet, it's a little hard to tell what this new Championship mode will do to improve our gameplay and what is just marketing rhetoric (no word on what it will do for achievements either), but it is said to include:
*Two points systems "to measure your skill"
* Enhanced Tournament Matching System that "offers improved tournament match making for beginners and mid-level players. Competitors earn Grade Points (GP) to earn entry into more advanced tournaments."
The downloadable alternate costumes packs are announced along with their release dates, each costume pack will run you 320 MS points.
2/17 - Brawler Pack
New alternate costumes for Zangeif, E.Honda, Rufus, El Furete, and Abel.
2/24 Femme Fatale Pack
New alternate costumes for Chun-Li, Cammy, Sakura, Rose, and C.Viper.
3/3 Shoryuken Pack
New alternate costumes for Ryu, Ken, Akuma, Gouken, and Dan.
3/10 Shadowloo Pack
New alternate costumes for Seth, M.Bison, Sagat, Balrog, and Vega.
3/17 Classic Pack
New alternate costumes for Guile, Dhalsim, Fei-Long, Blanka, and Gen.
Street Fighter IV launches on Feb 17 in North America and the 20th in Australia and Europe. So content may be on the marketplace before you can even purchase the full game.