Some PVP questions?

Hey, i've not played wow since before BC came out. i want to get back into playing again but everything has changed and i need some advice.

I want to start a new character, i was a rogue back in the day, so my specialty was picking on casters. but now i want to be one. and i want to be undead. so that leaves me with three choices.

Mage, Warlock, Priest.

I know they all have different rolls and such but i have been speaking to a few level 80's about pvp. they either say they do fine, or their class sucks for pvp. but i think its a bit more about knowing your class and what you can and can't do.

From what i can remember, mage's were good because they had good dps, and a few AOE's that helped out when their was a big scrum.

Warlocks didn't do all that well in pvp, but they did alright with DOT's

And Priest's speced shadow just melted faces.

I'm not sure about the way things work now, i would really like to be a shadow priest, but i've heard that their not really all the viable.

So out of those three classes which class is more suited for pvp with decent survivability. ( i also want to raid aswell, thats why i was thinking about a dual speced priest.) heal in raids, melt faces in pvp!.|||Discipline Priests are fine in PvP and likely will continue to be fine. I don't think Shadow Priests are all that great in 3v3s or 5s really. I don't see RMP going anywhere however. Which, incidentally, gives you another of the two classes you mentioned.

I'd reckon Mages or Priests are more likely to stay fine. Warlocks might make a comeback with the current slated changes, but currently aren't too damn hot.

All three are fine PvE-wise. However, if you want to dps in pvp, I'd suggest either the mage or lock over the priest.