Pristine Hide is the Arctic Fur of Cataclysm, they are used for epic LW recipes. Pristine Hide can be skinned from various low level water mobs in Azeroth right now. However, because they can't be used for anything yet, and more people are farming them, the price on them is dropping fast in the AH.
Right now they're going for 200g on my server, and may drop more. Think it will go for more than that when Cata hits? In other words, do you think it's worth it to snatch them up and resell later?