Sep 9th 2010 5:37PM Communism wouldn't be that big of a deal for the undead. Communism's problem is it results in shortages of goods and services, but the scourge don't really need much in the way of food, water, clothing, or shelter, so shortages are fine. Therefore, the only real barrier to an undead communist utopia is the whole mindless slave of the Lich King thing.
May 20th 2010 3:27PM Similar to what Transit was saying, the typical biological definition of symbiotic simply describes a relationship that affects both parties. Mutualism is a symbiotic relationship that benefits both, but it is often conflated with symbiosis itself. Parasitism is a type of symbiotic relationship that benefits one party and harms the other, so Blizzard is correctly using the terms.
May 20th 2010 2:47PM Not all races of priests follow the light, the spell names and animations are the same only due to game mechanics. New undead priests do a quest where they are told that they don't use the light for their spells, but their own willpower. It doesn't seem like too much of a stretch for goblins to be a similar kind of atheistic priest, perhaps using the all-consuming power of their own greed to cast spells.