Patch 2.5 is the prelude before Heavensward, the first paid expansion for Final Fantasy XIV, hits later this year. Also known as Before the Fall, this will be Part 1 of 3 for the whole Patch 2.5 update. Before the Fall includes roughly two-thirds of the final main scenario quests, three new dungeons, and the conclusion of the Crystal Tower questline and the World of Darkness.
Here is the official description for this awesome patch:
Eorzea stands to fall to chaos, from the shadows that gather over Ul’dah, to the darkness that threatens to cover the whole of the realm.
A most malevolent spirit stirs within the Crystal Tower, seeking to burst forth from the World of Darkness. Yet while this flood of shadows threatens the north, the Dark Divinity continues his ride through the Shroud. Can brave souls rise to stem the tide, and banish Odin from the forest?
Adventurers the realm over must rise up to aid the realm once again. There are many spoils to be had in new dungeons, much mischief to be made by helping Hildibrand─agent of enquiry, inspector extraordinaire─on his latest case, and great glory to be gained in joining the Scions of the Seventh Dawn against the evils of Eorzea.