Now you've had a week to dive about the Pandaren's land of bamboo and monasteries Blizzard are cracking open The Vault of Mogu'shan, a new normal level raid. The coming weeks will see the raid expand out into a harder instance, and gain functionality like the Raid Finder.
More details and Blizzard's schedule below.
This very eve, if you dare, you can creep into the deep dark vaults of Mogu'shan. The raid went live yesterday, but the Heroic version of the raid won't appear until 9 October; the first half will then appear in the Raid Finder. A week after that, on 16 October, the second half of the vault will appear in the Finder, letting you hop straight to the bosses (Of which there are five, and they look mean).
Then, another week later, on 30 October, Blizzard are opening the doors to two more raids Heart of Fear and Terrace of Endless Spring. Again, Heroic versions and Raid Finder will be activated a week later.