While the way the OP worded his post really undermines the point he raises, it is a valid one. The original design intents of certain classes (mages, rogues) were based along the lines of sacrificing the damage of the other pure classes (warlocks and warriors respectively) for more control. Fast forward to Cataclysm and you have a huge pool of homogenized damage dealing classes that can all put out roughly the same dps -- yet some classes have maintained the control that was supposed to compensate for the slightly lower burst or sustained damage.
Right now rogues and mages have the best of both worlds: strong damage and ridiculous control. Blizzard stated they wanted to reduce rogue lockdown and make them better at going toe to toe with other classes, and they did the latter part. Yet somehow they increased rogue lockdown while making their damage and defense extremely strong too. Rogues can play absolutely recklessly against casters and it doesn't matter because there is no way they can be killed if they are competent, and that's a pretty big sign that something is wrong with the current state of the game. While a rogue might not do the same damage as a Warrior, or even a Feral right now, Rogue damage is undeniably one of the strongest, and when you pair that with the ridiculously forgiving gameplay of Garrote/Kidney/Vanish/Cloak/Gouge/Mind Numbing, you have a class that IS technically overpowered, even if it's not sweeping the ladders (in the same way that Feral Druids aren't right now, despite them being way over the top).