Well, the "eyes" (if you can call em that, since it just looks like space and they could be comets on a collision course) look exactly like Lich King, but the ridge between does not. So what could it be?
And there's a Diablo 4, 5.. discussion (if you change the link, same for WC4), but this could be a major slip on their part.. If they remove it, we'll know they're hiding it!
Anyway, comparison pics, look between the eyes..