My melée team has the easiest time with this, turn on jamba follow strobe and run around like a retard until the core shows up. I then pop all cooldowns and kill him right as he retreats. My warrior, Mage, lock, shaman, priest team takes two retreats and the tank comes very close to death at the end due to sheer amount of adds on him and the inability of my priests instant heals to keep up with incoming damage. Thanks to this thread I haven't wiped yet!