It highlights the Tier 8 sets that can currently be found in the datafiles, which we've seen before but not in such a clear and simple video, with nice and (generally) neutral lighting. Death Knights, Hunters, Rogues, Mages, Warlocks, and Priests are highlighted, in that order. The last few classes don't have any skins (or hints of skins) buried in the game yet, so we'll need to wait awhile to see those. Out of the ones we can see, I'm not really sure which set is my favorite. They're all pretty cool and fit the class decently enough, except for possibly Hunters which is still cool but looks a lot like a Plate set for some reason. The Priest set is pretty amazing, so I'm definitely looking forward to getting my hands on it eventually.