I am just doing both. With my mages, I specced them frost, and the priest Holy, and lots of pulls so far (I'm mid 20s) are just Arcane Explosion spam, cycling frost novas, and throwing in Holy Nova for a bit of extra DPS/healing when needed (on a secondary action bar) With my Warlocks, I specced the priest Discipline, and it seems to be working out well so bar, (also mid 20s) My main team is 5 Shaman, whom I parked at 37 to get rested exp so I can get to 40 asap, while farming Scarlet Monastery a billion times to get all the scarlet chain gear, and 5 ravagers lol.

I did put the priests on separate accounts, so I could swap things around if needed, and do 2 priests 3x mages/locks, or swap a mage and a lock so each team gets portals and soulstones. Having the priest soulstoned has saved a lot of time on the Warlock team from many corpse runs, and I miss that on the mage team.

On my mages I Farmed SFK on saturday for hours, and got all 5 toons their Feline Mantle, Robe of Arugal, (I call him arugula) and the Belt of Arugal. I much prefer SFK over BFD, due to all the skinnable mobs, less casters, and no mobs that run away. I might go back there and farm another level or two, but will probably end up going to Gnomer before starting up Scarlet Monastery.

PvP wise, haven't done much yet, as I'm still too low, but I've oneshot everyone near my level, and killed a few above my level handily, so I'm looking forward for some Southshore vs Tarren Mill action in the future.