i've made it past this guy a couple of times. I have a pally and 3-4 shaman and sometimes a moonkin.
I place shaman and/or moonkin against the wall opposite of the room, between the harpon and the column, closer to the column. you don't get hit with his frost breath from here.
usually I can clear all trash without a problem from this place. I've even had my team drink once or twice while waiting for him to get back around.

once he drops I try to tank him at the entrace to the room so he's at max distance from my team.
when he spins he goes for my team and I stop DPS and hit him with the single target pally taunt ( the avenging shield didn't work for me... at ALL )
if you time it well, he should be at least 1/2 way to the team before your tank tants ( and I have winds shocks ready on the shaman )
this reduces the time he's on my tank if he wasted time headed to the shaman and wasted time getting back.
restart DPS when he stops spinning and most times I can kill him before he does it twice... most times.

not fool proof by any means but I usually get past this with only 1 or 2 team wipes.