During the Final Fantasy 30th Anniversary Event in Tokyo, Final Fantasy XV Director Hajime Tabata revealed when we can expect some of the upcoming DLC for the game.
On February 21, a special Booster Pack will be available to download through the Season Pass. This pack includes invincibility suits for the party that make them, well, invincible - but only for 30 minutes before requiring time to recharge. [Update: The invincibility suits have been delayed for legal rights reasons, and no details currently on when or if they will be available.]
On March 28, players can finally learn what Gladio went off to do during the game in Episode Gladiolus. During this episode, we'll also get to see more of Cor Leonis, who joins up with Gladio. Finally, Episode Prompto is set to launch in June, but no other details yet on that one.