4 shadow, maybe 5. Maybe a warrior or a shaman for the fifth. I think I like 4 for bgs better as I don't feel like as much of a drain, though still vitally important. I still plan to incorporate holy nova quite a bit, and may try disc instead of shadow eventually, but right now shadow seems too strong to pass up. Lots of burst and high survivability when you have 3 other priests nearby. The smite dynamic has been nerfed due to no more instant smites upon crit - smite spec isn't great unless they increase the range of atonement. However, using power word barrier may prove to be incredible survivability and synchronized penance for damage may make disc viable. I'm still betting on shadow even though my original hope was for lolsmite.