Final Fantasy XIV devs are always so forthcoming with contents of future patches teased on the game's official site. With patch 4.3 due out at the end of May, players are clamoring to know more about what's inside. So far, devs have been willing to show off a peek at the main scenario, the Alliance Raid Dungeon (Return of Ivalice), The Swallow's Compass dungeon and additional updates including cross-world Linkshells, Glamour Dresser updates and Guestbooks for housing.
Under the Moonlight is the forthcoming main scenario:
The arrival of imperial envoys in the land of Doma was as unexpected as their stated purpose: to negotiate peace. Lord Hien, eager to secure the release of his conscripted countrymen, cautiously accepts the agreement, and arranges for a prisoner exchange. Yet even as Doma is poised to welcome the breaking dawn, the shadow of the fallen Zenos enfolds all in darkness and uncertainty.
You can learn more about each of the things devs are teasing so far (with more to come!) by visiting the Final Fantasy XIV site.