Does shadow spec have any pvp potential? Without force of will?

Yes, Shadow spec is by far the best way to go for pvp as a priest. Concerning Force of will, I can't remember what that talent is off the top of my head, so can't help there atm since I'm at work behind a firewall =/

Yeah, I have a friend who is a 52 troll priest. He is shadow specc'd and wtfpwnz me ALL day. You can't cast on them because they have insane damage, you can't bear on them because they fear you if you get in melee range. In cat form, they fear you as soon as the stun from pounce breaks. . .really sucky.

Just get the PVP trinket and their fear is nothing :)

Its close though between Shadow spec and myself. I can usually win though, very few people can beat a Druid in decent gear.

Force of Will is rank 5/5 adds +5% off spell dmg and 5% crit to either all or just off spells.