Sorry if this is a repost, but I have not found anything on it yet. What you are going to be doing is the quest chain If there are survivors... started by Crusade Commander Entari at 87, 76 in Icecrown. Complete the first few steps until A Cold Front Approaches, do not turn it in.
Do not ever turn the quest in, you will be killing Forgotten Depth Slayer's and Forgotten Depth Ambusher's at 85, 74 in Icecrown. They have a nice drop rate of Nerubian Chitin, Borean Leather and Arctic Fur. The great thing is, they are not skinnable after you turn the quest in, making farming these less competative. Hope this helps those that are looking to get some nice leather for sale or crafting.
Again, sorry if this is a repost of a reposted repost.