Blizzard has just released the official trailer for Rise of the Zandalari which will be part of World of Warcraft: Cataclysm Patch 4.1.
There is also an interview with World of Warcraft Lead Encounter Designer Scott Mercer by Blizzard Insider posted at Blizzard that answers more questions about the upcoming patch.
The days when great troll empires stretched across ancient Kalimdor are long past. Millennia of war and internal strife have stripped these nations of their power, lands, and glory. As Azeroth recovers from the destruction of the Cataclysm, the world’s divided troll populations face a bleak future. These dark times have spurred the trolls of the Zandalar, the historically wise and scholarly tribe from which all trolls originated, to take drastic action. They have embarked on a bold crusade to save their race by uniting trolls into a single mighty empire. With the Zandalari’s aid, the fallen capitals of the Gurubashi and Amani nations — Zul’Gurub and Zul’Aman — are already rebuilding, replenishing their forces for a bloody campaign to expand their territories.
Yet Vol’jin and his Darkspear trolls are not aligned with the Zandalari. They have sworn to stand with their Horde comrades — and even work with the Alliance — should the trolls ignite a new war on Azeroth. Soon, Vol’jin might be forced to act on his promise, for if the Gurubashi and Amani are left to their own devices, the world will know the legendary strength and savagery of the ancient troll empires once again.