It's important that everyone knows which mob you're supposed to be DPSing down, and Domo should be taken off to the side away from everyone.
If I remember correctly, you sheep all the healers, kill 3 warriors, kill the healers and then kill the last warrior. Once you get that order down, it's simple and you can claim your phat lewt.
We killed Firemaw with 27 people last night.
