Please use this thread to provide feedback on the changes and additions included with the 5.1 update. This includes the new dungeon, its loot, and changes to the Raid Finder.
Also, we are currently aware of an issue with the Slithering Chaos dungeon. In rare circumstances, some trash NPCs may become unkillable. This is a known issue, and may be circumvented by leaving the instance for 10 minutes and re-entering.