The LotRO lorebook has been updated with information about the landmark of Sarnúr. Here is a portion of the article:

In Sarnúr, the Dourhands and their evil allies are mustering their forces to begin a final assault upon the Longbeards of Thorin's Hall and the Elves of Duillond. The dwarves of the Blue Stone Garrison have begun recruitment efforts to turn aside the wrath of the Dourhands by going on the offensive. Until the threat from Sarnúr is removed, the dwarves of Thorin's Hall will be able to lend little aid to the efforts against Angmar.

Sarnúr was created by the developers of The Lord of the Rings Online™: Shadows of Angmar™ as a public dungeon in Ered Luin, supporting the reputation system introduced after the game release. Players seeking to improve their reputation among the Dwarves of the Blue Mountains will need to take the battle to Sarnúr.

Check out the maps and screenshots at the link above.