Square Enix has confirmed that the first expansion for Final Fantasy XIV: A Realm Reborn is coming in spring 2015. Heavensward, as it will be called, will see a level cap increase from 50 to 60. Gematsu has a few story details, basing the new narrative in Ishgard during the thousand year war with Dravinia. If you want to piece together the plot points from the presentation slides from the expansion's reveal during the Final Fantasy 14 Fan Festival in Las Vegas, you can see them over on imgur.