The elementals are taking the fight to the capital cities.
The fourth and final phase of the Elemental Invasion has begun, and it looks like the elementals are taking the fight to the capital cities. Head over to Thunder Bluff, Orgrimmar, Ironforge or Stormwind to help barricade your home turf from the attacks, and then get your hands dirty by defeating all the elementals and taking the fight to the bosses via the Dungeon Finder.
For more details oh the Elemental Invasion, check out Wowhead's description of the entire event in their Cataclysm guide. You can also discuss the event in our WoW general forum. If you have any screenshots from the event, feel free to submit them!