There are two important things to realize from this newly discovered information. First, it shows that Blizzard is hard at work on Wrath of the Lich King, and is already starting to include content in the patch files. We saw this same behavior in patch 2.0 with Jewelcrafting recipes.
Gallery: Wrath of the Lich King
Quite a nice little preview at WotLK content. What do you think of this glimpse at things to come?
Gallery: Wrath of the Lich King Concept Art