an entire game's worth of content was supposedly cut from Final Fantasy XIII, one could imagine there's a veritable gold mine of content waiting to be polished and released as DLC. Apparently not, however, as producer Yoshinori Kitase has allegedly indicated, "at present we're not considering [DLC]." The quote is said to originate from a brief interview featured in an Ultima Guide for the game (via FFReunion), and Kitase apparently added that DLC is still "possible," but it's just not something Square Enix is working on right now.
Kitase cited the team's drive to create a complete experience in the final retail game as one of the contributing factors to putting DLC plans aside. He also pointed to the game's exceedingly long development time and the developers' focus on getting the game finished as soon as possible. Clearly, "asap" has a different meaning in Japan.