I want to make a thread about the potential role of Bolvar in the upcoming expansion. There's a lot of visual information in just the bottom 2 images:
Cinematic shot - a theme of blue and orange. Blue eyes, orange fire in the body and hammer. Daylight on the mountain to the left, shadow and ice to the right.
Logo - cold blue steel frame with what looks like orange/gold melting around the edges.
Concept art - blue and orange
I think Bolvar isn't the Lich King 2.0 everyone is expecting, but instead a gatekeeper between the worlds of life and death. One of the weirdest things in the history of WoW was "There must always be a Lich King", and I guarantee the writers are trying to rectify this by not exactly retconning it, but reexplaining it in a a different way.
Terenas said "the scourge would run rampant without the master at the helm". Maybe when it was originally written, it just meant the existing undead and ghouls would just spread across Azeroth wildly and uncontrolled. But that really made no sense that the Lich King would've been preventing that willingly. Based on the stuff we've seen I think they're going to retrofit it to mean "Someone needs to be at the helm of the damned to keep the death realm at bay" or something along those lines.
We can probably expect Muehzala to be mentioned and one of the purposes of the gatekeeper (Bolvar) is to stop him from gaining access to the life realm.