Here are the Release Notes for Update 21.
Of Special Note:
Epic Volume 4: Book 9
Witness the fate of the One Ring and Sauron! The Epic quest line reaches a major milestone, and remains free to all players.
The Black Book of Mordor
We begin a new story in Update 21 that will continue in future updates. Travel beyond the Black Gate, seek treasure and conquest, and discover what happens when the Free People enter a land of evil and corruption.
Explore Mordor... read more here