The event is called "Heavy Metal," and here's how it will work:
When the Heavy Metal live event begins on November 17th, players who log into WAR will see a new tab in the Tome of Knowledge. Clicking on this tab will open the Live Events page, where each day we'll place a new daily task. Completing these daily tasks earns influence, just like you'd earn in a public quest. There are rewards for Basic, Advanced and Elite influence, culminating in the ultimate prize: the chance to play WAR's new classes a full week before they're released to the public! This last reward won't be easy to earn, and players who want to get to the Elite level will need to log in each day and complete on the daily event.

In addition to the daily tasks, a new scenario will be online exclusively for the Heavy Metal event:
We will also be adding a new scenario, Reikland Factory, for Heavy Metal that will only be available to players for the duration of this live event. This scenario will take place in a steam tank factory in the Empire Tier 4 zone of Reikland and see players battling for control of different areas of the factory. This new scenario will be available for players of all levels, on all tiers, but will not contribute to the campaign. Participation in this scenario will give players an extra 10% bonus to their Renown point gain.This is a clever bit of counter-programming from Mythic that keeps the game's momentum moving forward and aims to keep players involved despite the launch of World of Warcraft's Wrath of the Lich King expansion a couple days before, on November 13th. We'll have more details on the new classes soon.