>we see someone using actual shadow priest abilities like MIND BLAST in a cinematic, along with super HD Voidwalkers
neato
>giant paladin army of the light outta nowhere

I'm pretty sure this is how they're introducing the Arathi Empire, using the Sunwell as a portal. They were an actually interesting new lore bit teased in the last xpac. They're descendants of humans who left their homeland a long time ago, they have a super militarized religious empire on another previously unseen continent. The new humans from the last xpac like that one eyed one armed black chick are from a lost colony of them.
Meh. We'll see how it goes. It's the gameplay that always matters.

I'm just honestly happy that Lor'themar or Lady Liadrin did NOT die in the cutscene. My expectations are so low.