Call me stupidFollow

... But, I just want to know. When the alliance got shamans, what happened? I heard that before TBC they were OP in PvP, and afterwards... something happened.

What gives?

PS: Im gonna be posting some more questions in here soon :)

Nothing happened. They were just never that good; certainly not as good as Paladins were in the BG era.

Nothing changed. Before there was an illusory imbalance because players of one side were constantly upset that players of the other side had something they didn't, even if they themselves had something to compensate. If you were on Alliance and a Shaman beat you, it wasn't "oh, I guess he got lucky" it was "goddamn Shamans are OP."

Those same people might go roll a Shaman on a different server and then it's all "Goddamn Paladins and their goddamn bubbles! That is so OP, I'll go swamp the Blizzard forums with my facile analysis of the situation."

See, now both classes are considered mediocre and good only for healing. Equality for everyone!

Shadow priests are what were overpowered at 60 in PvP. The one really annoying thing about shammies was they you couldn't run from a shammy once they got Frost Shock on you once, because they'd always be in range to reapply it as soon as it wore off.