The next major update for {Final Fantasy XIV: A Realm Reborn} - Through the Maelstrom is set to launch on March 27. There is the main scenario (Through the Maelstrom) and two side story quests (starring Hildibrand and Gilgamesh). There is the Leviathan to defeat, Beast Tribe Quests, three Dungeons (The Lost City of Amdapor, Halatali [Hard]. and Brayflox's Longstop [Hard]), and naturally new gear.
The Lost City of Amdapor
Halatali
Brayflox's Longstop
The Second Coil of Bahamut
You can find a full rundown of the new content on the official website.