The first char I ever leveled to 60 (this was long before BC) was a shadowpriest (I had gotten a warlock to 55 and a druid to 52 before that). At that time instance-dps wasn't viable as shadowpriest and all I ever got to do was heal heal heal, and I didn't do that good either, since I was meant to kill really! So pvp was a blast and everything else sucked...
So I decided that if I ever was to do what I really wanted, to inflict pain and suffering (not only onto other players, but onto the rest of the world as well), I had to leave my dear shadowpriest behind. I rerolled warlock (again) and worked my way to 70.
After a while I looked up my old love the shadowpriest and decided I wanted to play her again. This time she was gonna be holy tho, since I already had my dpser the lock. But with BC they actually made shadowpriest work in instances! People actually -ask- for them and -like- them. I was stunned. My priest is holy and has nearly no dpsgear (and it all sucks). Respeccing means endless runs to get reasonable gear. No, I wanted to do this from scratch.
Unfortunately I've already filled my mainserver with chars, so I had to start one elsewhere. Now I have, on an rp-server so the damn gankers won't bother me EVER AGAIN!
And I love every second of it, shadowpriest has always been my calling! (Altho I love warlocks too).