There has been a video that presumably was showing a low level Warrior walk up the stairs to the Frozen Throne and buying Frostmourne from a crystal vendor next to the throne. It's from a german fansite, and it is not footage from the expansion. This is of course good and bad as it's good that we won't be seeing any such bad quality graphics in Wrath, but also slightly sad, as we are absolutely aching for more Wrath of the Lich King information.

In a way you can look at this as a bit of a teaser. The Lich King Alpha has started, and we will probably be able to see a very playable version at WWI Paris in June. There will probably be more info available either from leaks or released information from Blizzard very soon.