Emalon the Storm Watcher is the new boss in the vault of--what? You were expecting Algalon today? Well since no one has downed him yet I'm going to say that I'm not qualified on telling you how to fight him. And besides Emalon is a good boss too!
Emalon is not a loot piñata, this should be made clear at the beginning of the fight. He's pretty simple once you've got the fight down but understand HE IS NOT A LOOT PINATA! Ok so he has some adds that should probably be picked up by an OT, but if your MT is geared they can be tanked by the MT as well. He will do a Lightning Nova that all melee needs to run out of. He will also occasionally overcharge one of his adds and if it is not killed fast it will wipe your raid. I know some people say that your OT should be able to mark the add for the dps, but come on. If you can't target the add that is 3 times larger than the rest you are--well I don't want to be mean so you're just bad at targeting large things. Rinse and repeat until desired effect.