According to GoNintendo, Capcom is not ready to announce the long-expected G/Ultimate version of Monster Hunter X, as has been the franchise's tradition. The company feels that players would just wait for the expanded version of the game, so announcing a new version immediately is not viable.
Monster Hunter X's DLC will have the same quest system as the game. There will be new quests released on a regular basis for free, as there were with Monster Hunter 4 Ultimate.
Capcom, like most companies, wants players to be interested in the game for an extended period of time, especially because extra content was one of the reasons MH4 Ultimate sold well in Japan.
Monster Hunter X arrives for the Nintendo 3DS on November 28.