We have one more week of the Iron Horde invasion event before we can take the fight through the portal to Draenor. Most players seem to think this event is serviceable, if unexciting. Like all such events, it lives in the shadow of the most memorable pre-expansion event in WoW's long history: the zombie plague. It debuted almost exactly six years ago, and Blizzard has never topped it.
If you need evidence, just look at the comments on the previous WoW Archivist about patch 3.0. I only mentioned the event in passing as a topic for a future column. Even so, readers posted more about the plague event than about any of the other 3.0 features like achievements, glyphs, or pally nerfs.