At one point I toyed around with a Holy-Crit build, for a solo priest.
Took the talent for faster casting of Smite, Holy Fire and heals.
I'd open with Holy Fire, SW: Pain, Mindblast and then Smite spam.

Use PW: Shield to get spells off without too much spell pushback.
They had a talent where you had a 50% chance to get an instant cast smite from any crit.
I'm not sure if the talent is still around or not, but did not notice that when I was messing around with priest builds recently.

Assuming I finish my RAF leveling prior to WotLK, I'll be doing a priest team next.
The shammies are mid way through 68th and will go to 70th before I do anything else.
The hunters are 55th will RAF 300% exp's and will stop at 60th for now.
The priests will go as high as they get to, but RAF will likely run out, while I'm leveling my shaman and pve teams from 70 to 80.

Pretty sure my priests will be mostly discipline, two points in holy for the pushback resistance on heals, and 11 in shadow for mind flay. A mix of Holy Fire/Smite, Mind Flay/Mind Blast, SW:Pain/Devouring Plague for the dps.

To counteract fear on your priests, you can use Fear Ward on a castsequence with a reset.
Fear Ward is a 3 minute reset normally, but is 30 seconds faster with the Glyph, probably worthwhile to negate Fear-Bombs. 2.5 min buff with 2.5 min cooldown.

So you'd have:
Press 1 = Priest 1, protect Priest 1.
Press 2 = Priest 2, protect Priest 1.
Press 3 = Priest 3, protect Priest 1.

And Priest 1 would protect the rest of your team, by having Mass Dispel on a very easy to activate keybind. Not sure the level you get mass dispel, but its not early in your career. Until then, you'd probably have two hotkeys for Dispel Magic, with each priest dispelling each of the other two. It could be a single macro if you wanted:

1:
/castsequence [target=priest 2] Dispel Magic,,
/castsequence [target=priest 3] ,Dispel Magic

And the same on priest 2 and 3, except change the targets.