Predictions on the Crimsonwood Keep expansion?

Since Masteria has traditionally been the mold-breaker of all of MapleStory so far, I could easily see the next area being a huge RPG-style "final boss" like area where you have to plow through hordes of enemies. On top of that, I could see them doing something (which would be REALLY cool) where you fight alongside the soldiers in the imminent war spoken of by Jack Barricade and other NPCs in the new CWK quests. These warriors act like a secondary party, and are basically NPCs fighting with you, using new skills and other awesome stuff.

At the end I'd love to see the first-ever multi-boss fight, where you have to fight all 4 GrandMasters at once in a giant, 2x-the-size-of the Zakum map or something like that. A grand final showdown for an amazingly cool and difficult place.