Hearthstone Blizzcon Teaser hints at Lich King expansion

The official Hearthstone Twitter account just dropped a video which heavily hints at a Lich King expansion coming to the game, and maybe to World of Warcraft.

In the teaser we see an orb that shows Dalaran and Dragonblight, and the lady talks about a conclusion coming to a battle. She explains that we have to chose a side in this conflict. This sounds a lot like World of Warcraft Lore as it currently stands. The lady might reference to the conflict between Sylvanas and the leaders of the Horde and the Alliance. Next to that, there have been a lot of rumors and hints towards the Lich King playing a big part in the next expansion.

Check it out for yourself:

What do you think, is this teaser just for Hearthstone or could it be for World of Warcraft as well?