The rogue is the most feared class in player vs. player combat. While other classes may have had their 15 minutes of fame at the top, the rogue has been perennially powerful. In WoW, we were so hated that an entire video series was dedicated to how overpowered we must've been. In The Burning Crusade, the legendary Warglaive combo made us infamous in arena play. Death knights did dominate in the early stages of Wrath, but rogues came back strong throughout the patches.
Cataclysm was the first time that I ever worried about the survival of the class in PvP. With health pools skyrocketing again and the much-maligned stunlock nerfed, it was obvious that fights were going to last longer than ever. Our energy system enables us to keep up offensively for an indefinite period of time, but our defenses typically gave out once our cooldowns had been consumed. Figuring out a way to stay alive throughout prolonged combat was going to be the key to success.