Venture Co are treated rather normally this expac, save for the ones we fight in the Meadery. I assume they will be our ally renown in Undermine, letting us work with Gallywix (who despite being a bad dude isn't a straight villain), and the Darkfuse Company will be the villains due to their set up in the campaign and the name having ties to both the Void and the Blackfuse Company (who were the goblins who influenced Garrosh's True Horde and Iron Horde)
The goblins making the Dragon Soul is too clever of a tie-in to this expansion for them to pass it up, and seeing as the Dark Heart is in need of repairs right now I assume this is the next major patch with the Haranir being the finale.