GameStop posted an image of the rear cover for the Final Fantasy XIII case for Xbox 360, and "game content download" is one of the highlighted features. Is this a confirmation of DLC?
Honestly, I'm not sure. (Get a closer, if pixelated, look here) I've emailed a Square Enix rep but it's the weekend. I went back to a few of my most recent cases from 2009 for games that featured DLC. Dragon Age: Origins, Assassin's Creed II, Brütal Legend and Madden NFL 10 all carry the "game content download" designation. (Curiously, Borderlands does not.) That all speaks to a wide range of content.
The last we heard of this, Square Enix was considering DLC but its plans were "unclear". That was as of August. Sounds like things may have cleared up?
Gamestop Unveils Back Of Final Fantasy XIII Case (Xbox 360 Version) [GayGamer.net]