The name of a huge convention hosted by Blizzard Entertainment which is a creator of the online game World of War(WoW), where a number of fans/geeks (mostly obssessed with the game) gathered.
Fan A: Blizzcon was AWESOME!
Fan B: Yeah totally.
Friend: What's Blizzcon?
Fan A and B: IT'S THE MOST IMPORTANT CONVENTION IN THE AZEROTH!