Visit the World of Warcraft forums and you'll invariably find post after post about how some class is over-powered. Dig deeper into the thread and you'll see that the majority of these posts are in regard to arenas and battlegrounds, and especially 2v2 arenas. Arms warriors and feral and restoration druids are the most common targets of the hate - and for good reason.
To avoid diving into the theorycrafting, I'll cut right to the chase. Arenas are broken. Druids and arms warriors dominate arenas due to the broken mechanics of the arena subgame. Every other class requires a very cookie cutter build to even hope to compete. Despite this level of homogenization, Blizzard still has not properly set any sort of gear-leveling match making.
Despite whatever Blizzard wants, the Arenas are not an e-sport. They can not compete with FPS and RTS games. I don't think Blizzard should even be trying to mold World of Warcraft into something to rival the CAL.
This is World of Warcraft - a rich universe of story and background and feel. Players should engage in huge battles for bloody inches of ground. Battlegrounds are somewhat successful but Blizzard really needs to implement dynamic world PVP goals with rewards based on their rich history. A visit to Alterac Valley or a quick visit to the arenas demonstrate that neither fulfill the promise of the world that Blizzard has so painstakingly created over more than a decade. In this player's mind, the battlegrounds and arenas are not "true" PVP. We need perpetual and dynamic battles with some real rewards that will help players in both PVP and PVE.
Now, you might ask, why don't you just play on a PVP server? Therein lies the issue that Blizzard can not resolve with mechanics - human nature. Ask people from PVP servers what the experience is like and they will tell you it's a gankfest of 70s destroying players trying to level. Mythic has the chicken mechanic (http://warhammeronline.wikia.com/wiki/Realm_versus_Realm) which has some effectiveness but it's not a total solution.
Lake Wintergrasp in Wrath does show some promise and may be the best way to ensure some fairness (after all, it is a game) and still have solid, rewarding world PVP in World of Warcraft. The final implementation is yet to be seen.
Ferals are fine, but restos are over-represented in 2s and 3s. Ferals are kind of gimped by how they function and the synergy they can't use (no weapon procs, no wf, etc.). But they can last a long time. Restos are simply difficult when they can heal and shift into bear and Feral Charge. Due to the 3+1 instant heals they have (2 of which are hots and 1 on a 2 min timer), they are difficult to shutdown. Combine that with smart LoS and, yeah, gg. No other healer can heal others and themselves as effectively and while being focused by enemies right now.
There really is no war in Warcraft. Heck, the factions share a city in BC now. And no real world PvP to speak of. I have hopes for LW, though. But I will be playing WAR also to get a much better RvR experience. Right now, WoW PvP is a sandbox of arenas, racefest AVs, poorly implemented CTF,
and 2 decent bgs in AB and EotS.
Another point. If you make something exclusive that is desired in an MMO from a particular mob/scenario/raid/etc. people will do it to the exclusion of other things.... Case in point Arena. A lot of people don't like it and even hate it, but they do it. Why? Because it is the only way to get the best PvP gear. THE only way.
All things being equal, the same top end PvP gear should be available from Arena, BGs, and World PvP. Then you could see what people actually enjoy and what they don't based on what they actually play.
Comment: well how about ratings.... well, come on. Arena has ratings baked in... in a broken way that is a ladder based solely on winning more than losing to the exclusive of everything else. Same with BGs then if you wish. Just keep track of record. Or even better, base it on ranking on dmg/heal/KBs/HKs. For World PvP, let it be based on K:D where HK is involved (so you can't gank lowbies and get better ratings. Easy to take HKs into account for rating purposes).
Personally, I like the WAR method of Renown accumulation and no decay that is available from all methods of RvR equally.