"Why Highmaul?" is one of the most frequently asked questions I get these days. It does seem a little strange that we are raiding the capital of ogre civilization when one would think we should be facing down the leaders of all of the Iron Horde we've been fighting against throughout the leveling process. But there's method and reasoning as to why we're invading the ogre stronghold, and it absolutely ties back into the Iron Horde.
When one thinks of ogres, one hardly thinks of things like intelligence or cunning -- it's usually the complete opposite. But the ogres of Azeroth are a far, far cry from what they once were, not so long before the events that opened the Dark Portal and began the First War. The Draenor we're currently visiting may be a slightly altered universe, but the history remains by and large the same. And in both instances, there was a point in time where the ogre race ruled supreme.