said by Immer:sounds like an LFR macro is in order:
/rw DPS: Try to stay in one of the dotted green circles around a leg
/rw dps the leg until it is untargetable, then switch to a new leg
/rw when all three legs are down, target the body until a leg comes back
/rw Healers: stay within maxed range from the tank (the guy with the pheromones debuff)
/rw Everyone: Stay out of the purple circle under the boss. I'm looking at you, melee!
In my case ranged and healers were the dummies to stand in the purple circle because the boss moves around and they standing still pew pewing or healing, melee usually follow the legs.
I tried all week and even with the hotfix nerfs we can't get him down, that's when we get at least 23 people in raid, most of the times we wait for people to queue, 95% of them decline a 2/3 run.