It would be totally awesome if they made an (almost) unbeatable boss go insane on major cities and killed EVERYONE. If they seriously come up with some lame boring event where a few people dies and thats it, wow that would be lame.
Its 1 of the reasons wow is boring now. blizz never does anything that might kill us. "yay look at me im killing mobs for this quest!! omg im BBQ chicken!! if something interrupts me im gonna ragequit wow qq"