That’s right, as of early this afternoon the Cataclysm World Event launched. The above picture is dialogue from Doomsayers in Stormwind, where all the Alliance leaders have gathered to discuss the situation. The Gnomes are moving out of Ironforge, while the Stormwind army is speaking to heroes to thwart the allegations made by doomsayers and the Twilight Cult.
Rifts are opening in various zones throughout the land as well, with elementals pouring out from within them. Disposing of them will allow you access to the mysterious devices that have also begun showing up in various locations.
It has begun!