The Elemental Invasion brings about the end in small, bite-sized, chunks.

Don't worry though, the fun's not done once the cities are safe. Each type of elemental you fend off unlocks a boss that you can down with four other friends, or use the LFG tool to find a group. These bosses give 16 Justice points and ilvl 251 gear, so use this chance to gear up those under-geared alts for leveling in Cataclysm. It sounds like quests will be more difficult in the expansion.

Each of the four bosses is pretty easy.  Flame Ambassador Flamelash (fire) has an AoE short stun. Casters should stay back from him. Prince Sarsarun (Wind) unleashes two tornados that bounce you up in the air. Crown Princess Theradras (Earth) randomly throws rocks. And lastly Godzilla Kai'ju Gahz'rilla (Water) places ice on the ground under your feet. If you don't move you will be shot up into the air. Each of these bosses is available for 30 minutes after you defend your city.

This is the last phase before the Shattering. I expect about a week of this, or maybe a little more. Then the face of Azeroth will be changed forever.  I'm looking forward to it. Are you?

~BeanX
Yes that is Black Magic enchant on my OH. I was testing some numbers and haven't got around to changing it back.