The most striking think about this description is that it looks like the Alliance will have no big roll in this event. Which is probably intentional if the attack was a surprise attack and things were happening so fast Jaina didn't have time to call for help.Spoilers Ahead! - The rest of the post contains many of the quests from Mists of Pandaria, so don't continue reading if you don't want to know what is going to happen!
Theramore Scenario
At this point is is very likely that we will see the previously mentioned Theramore Scenario at some point, as it was mentioned as a possible event for the pre Mists of Pandaria patch. We came across some of the quests related to the event, which reveal a few details.
Important - This scenario is not complete and will likely undergo significant changes before it is playable.
The Horde are attacking Theramore from their airship, The Fist of Garrosh, which is captained by Sky-Reaver Stormhowl. The Horde must first enter the Foothold Citadel and slay Captain Hedric Evencane for his key. This key allows you to free Thalen Songweaver, a Sunreaver mage who was spying for the Horde.
After the spy is free, you rig explosive barrels in the ships of the 7th Fleet while Captain Drok holds off the Alliance forces. Blastmaster Sparkfuse then detonates the explosives, disabling the ships and allowing the airship to move into the harbor.
Next you must slay Baldruc the Gryphon Master to prevent the airship from being attacked by gryphon riders. Once this is complete, you move on to the final obstacle, the steam tanks. These are destroyed by bombs or direct attacks on Big Bessa. Captain Drok of the Sea Wolf then will attempt to reduce Theramore Isle to rubble.
If Alliance players do get a chance to participate in the event it'll probably be to help get survivors, fight of left over Horde npcs, or just run off what Horde invaders are left to reclaim Theramore.
