I just have to ask, my curiosity is killing me. Why would you spec your priests holy for pvp?

If you went Shadow you'd do decent pvp damage, have silence and a better fear. You could also dual-box dps in instances and raids.

If you went Discipline you'd have amazing survival abilities for pvp and still be able to heal very well in instances and raids.

I know a lot of folks got used to the whole insta-spam circle of healing thing, but that has been nerfed. I just don't see the advantage for being holy (haven't in a long time actually).

*edit fixed grammar error*