I kind of agree with this.  Hunters are able to kill the most classes with ease in my opinion.  A pain for warlocks is a warrior (at least it is for me right now).  They charge and stun, when you fear they use their trinket, fear again and they use Bloodlust (I think that's the name) Try and fear again and it reflects on you.  During this they pop you for 2-3k on average and even with almost 11k hit points unbuffed it makes for a quick death. 

Rogues aren't AS hard for me anymore unless it's a mace carrying rogue and they just stun lock me.

Druids are not a problem anymore for me.  It used to be a pain for me to kill them until I learned how to beat them. 

Pally's, they're not DPS Over powered but they are healing over powered.  It's ridiculous that they can pop that bubble and be immune to EVERYTHING for 10 or 15 seconds, whatever it is.  It should be made like the priest's bubble where it absorbs damage, not Immune.  While in the bubble they can heal, once out of the bubble if you get them almost dead they can use Lay on Hands which heals them 100%.  So, Pally's are more of a pain in the @$$ than over powered.

Each class has their own strengths and weaknesses.  If any class seems to be op to you, it's because you have not learned how to exploit  their weaknesses against your particular class.  Only time, and skill development will dispell the OP myth.  Locks are definitely not the "Most Overpowered Class".  Most low level players think that they are just going to run up to a warlock and start kicking his/her head in.  After taking many fear casts, and shadow bolts they claim "Warlocks are OP".  When their toon is actually "PP" = poorly played.

How fast can u die? A pally or priest can heal fast, so kill em twice...b4 u die. Try to DOT 20,000 hp with 10,000 armour to death (warrior/rogue/druid/shammy) lolz . And anyone thats done any BG prob has a fear trinket, so fear now sucks. As far as hunters go, welllllll, I was doing one of the first dailies at 70, I just sat down to eat/drink, when suddenly I see my hp drop to about 1/2, by the time I turned around to look and see a Hunter off in the distance, I was a ghost. Needless to say I was disgusted. I checked the combat log - first shot crit for 3000, second for 2k, and a couple more quick shots, did me in. Didn't even see his pet. Death in 2 seconds is kinda UP, not OP, even if my gear sucks and he had epics (I'm guessin'). Locks need leather too, even partially.  Even just yesterday I had 2 stealthed gnomes kill me in 2 seconds. Needless to say I was disgusted. It takes time to get decent gear, and you need good gear to do any arena, so I'm still workin on it (points). My hunter's at lvl 35  now lol . Once again it's about the gear and how well you play.