According to an update on the official Turbine twitter page, The Lord of the Rings Online: Volume 2 Book 8:Scourge of Khazad-dûm will go live on June 23rd, 2009. In addition, patch notes for Volume 2 Book 8 are now available on the LOTRO website.

Epic Book 8:

The plans of Gorothúl, sorcerer of Dol Guldur, begin to be made clear as ancient evils stir again in the depths of Khazad-dûm. Small fellowships must form to combat this emerging threat before the hopes of the Iron Garrison and the Elves of Lothlórien are ended by the darkness. The story of The Mines of Moria continues with new quests and challenges!