I'm pretty much with Stealthy on this one. My current preference is more toward the PvE side while leveling, so I didn't yet put anything into destruction and took insta-corruption, Imp. lifetap, Imp. drain life and 2 points in suppression.

I also prefer to run 4 felguards as just them alone can chew up a rogue or squishy pretty handily while I'm doing the DoT-fear tango with another. Hell, I killed a 70 pally yesterday in Terokkar with just 3x CoAgony and the felguards while I dispatched his druid buddy. I've gotta start videoing this stuff. :P

My priest spec won't change much from what it is now except to pick up surge of light and a few other miscellaneous things with leftovers.