It's actually 6 in the video, and suvega (naked) as the noncombatant cameraman.

It took about 20 minutes to kill him -- you have to make sure not to pull dps from the rogue tank (whose TPS isn't exactly spectacular), and it's mostly about survival rather than flat out dps.

The rogue is a pure avoidance tank -- he should never get hit. Our healer (paladin) is there to top him off if he's unlucky with the cave-ins, and the shadowpriest will bubble him. He's allowed one "mess up" every cheat death cooldown.