The final part of the Elemental Invasion has begun. The events are a little tricky to start out, but once you have cleared the cities you can queue up to face one of 4 different bosses (2 will be available at a time). There is a quest available from either Varian or Magni for the Alliance to defeat the boss, which is turned in back at Ironforge or Stormwind (Haven't done Horde side for this part, so you'll have info about that section elsewhere). You get ilevel 251 gear (initial Tier 10 equivalent) from the bosses, so if you have some level 80 characters that haven't run ICC yet, here's a chance to get some new gear.
Good Luck and have fun.