Our friends over at Adriacraft have been busy digging through the files, and made a video showing the inside of the Siege of Orgrimmar. Now, it should be noted that this is very, very preliminary. It's a 3D flythrough, there are several textures not yet in place, there's no lighting there are no mobs, and so on. But nonetheless, it's possible to get a feel for the raid environment. It seems quite dark and indoors-y, as secret underground lairs often are.
The section we're looking at is accessed via Ragefire Chasm, and it looks like Garrosh has been very busy creating an underground city. What we're not 100% sure of at this point is just how this will tie in with the raid entrance we saw yesterday in the Vale of Eternal Blossoms. It may well be the case, as we've heard that the raid is in LFR-style sections, that the first set of bosses is in the Vale, then we're sent over to Orgrimmar to bring the smackdown to Garrosh in retaliation for his actions. What do you think?