Beginning on October 23rd, a series of events started rolling out across the World of Warcraft servers, a kind of premonition for the upcoming Wrath of the Lich King expansion pack. For a couple notorious days, zombies infested all the major towns. The Horde and Alliance have recovered from that assault, but the Lich King's attacks continue elsewhere. Now the opportunity is there for players to acquire some nice epic gear for their characters just in time for the expansion.
The mechanics of the event should feel familiar to players who remember the Scourge Invasion event that took place when Naxxramus was released. But the rewards are significantly better.