Blizzard Entertainment have announced that the Mogu'shan Vaults have now opened in World of Warcraft: Mists of Pandaria:

"The first Normal difficulty Mists of Pandaria Raid Dungeon is now available: Mogu'shan Vaults. Raid Finder and Heroic difficulties will be available Tuesday, October 9.

Raid Finder will unlock bosses in Mogu'shan Vaults and Heart of Fear over time, and all Mogu'shan Vaults bosses will be unlocked and available Tuesday, October 16. To access the new Raid Finder dungeons, you will need a minimum item level (ilevel) requirement of 463.

Here is the current schedule for these Raid releases:

Tuesday, Oct. 2 - Normal Mogu'shan Vaults

Tueday, Oct 9 - Heroic Mogu'shan Vaults and first half of Mogu'shan Vaults on Raid Finder

Tuesday Oct. 16 - Second half of Mogu'shan Vaults on Raid Finder

Tuesday, Oct. 30 - Normal Heart of Fear and Normal Terrace of Endless Spring (Must clear Heart of Fear first) with Heroic and Raid finder versions unlocking one week later

We will update this post with additional unlock information at a future point in time."