This sort of thing happens just before the raids, too. One guild member will pull out a D.I.S.C.O. ball, another will start throwing around Party G.R.E.N.A.D.E.s. Before you know it, the dank corridor that leads into the depths of Icecrown Citadel has suddenly been turned into a happening place to be, the ground littered with "Spectral Tiger" mounts, Ogre Pinatas and kettles of Goblin Gumbo. Sometimes Archmage Vargoth puts in an appearance. He can't help it; there are usually four or five flaming draenei dancers congregated around a Brazier of Dancing Flames, and the girls just drive him crazy.
Does stuff like this happen on your server? Spontaneous dance parties, mammoth trains, stacks of flying mounts hovering above the Dalaran well? What happens when your server gets bored? Trade chat aside, mind you -- we all know how /2 gets when people are feeling feisty.