Straight from blizzard and a blue post:
The Battle of Theramore, the first of many Scenarios coming to World of Warcraft, is a story-changing event that will be available to level-85 characters for one week only — the week leading up to the launch of Mists of Pandaria on September 25.
For the duration of the week of September 18-24, level-85 characters will be able to queue up for and participate in the Alliance and Horde versions of this new Scenario with two friends. (Please note: if friends are not available to you at the time, two will be provided. Batteries not included. Subject to change. Void where prohibited.)
After the lifting of the mists, the Battle of Theramore will join all other Scenarios as level-90-only content, and everyone — including players who missed it at level 85 — will be able to play through the event. Upon completing the Scenario for the first time, players will see the aftermath of the battle whenever visiting Theramore in Dustwallow Marsh. Theramore will eventually be changed permanently to its post-battle state in a future patch, sometime after the launch of Mists of Pandaria, whether or not players have completed the Scenario.
We’ll see you there!
Phasing tech at work! Did you catch that? Theremore will only change when you privately play through the scenario… at least until sometime during Mists.
Alliance characters get a special tabbard to plant into the ground and horde players will get a mana bomb. Now I’m wishing I had a toon at level cap on both sides!
See you in Theramore!