In regards to the last boss on heroic mode, I've found that the only real way to take him down is to do it QUICKLY. The main problem with the last boss is the fact that he doesn't really have a real agro table like any other mob. As the person before me stated, he runs around and hits people that did not even necessarily hit him at all. What makes this fight even worse are the adds that constantly flow into the fight. The group that I was in that had success has a rogue (well-equipped), taking down the adds, and bandaging whenever possible, so as not to detract from the healers attention to the tank. I suppose a hunter would also work for the adds, but I think that a caster would find more success just nuking the boss and taking him down as soon as possible. Another thing is his attack where he charges people and  does a good bit of damage to them. There is no real strategy against this so you really just need to not QQ about it and bandage or heal up and keep nuking.