When you talk about pvp, do you mean world, battlegrounds, arena, or dueling?
World PvP generally goes to the aggressor, which is why whenever I see a rogue I either kill them or mount off. Feral Druid, usually mount off, but we'll see after the patch. Stealth is overpowered in this environment. Gear matters and matchup are very relevant, but if you're getting caught off guard or with a mob, the odds are already against you.
Battlegrounds are balanced and have been for a very long time. Tactics and execution trump all, including gear.
Arena's are harder to balance. I've never been one to 5v5 so I can speak to balance there, but 3v3 is balanced most of the time. You win based on your ability and a little luck except for against this one-comp where you've got little chance to win and this other comp where you could roflstomp them with your eyes closed. Gear matters, but it isn't going to carry you.
Dueling is like world pvp without as much advantage to stealth. Some classes are just the rock to your scissors.
But yeah, being a priest has always been "special" in pvp. I remember back when I rolled out in the full Ironweave set, ZHB and some other tanking trinket I can't recall. I was pushing 75% damage reduction versus melee with trinkets proc'd.
Switched out the shoulders and the wrists (I think) for the ZG ones that increased smite range to 42 yards. You could spam 1 second rank 1 smites on flag cappers from beyond anyone's reach.
Good times.
