Hi there, long time no see *insert random long and most likely boring greating sequence*,
let me state a hypothetic (or fast hyphotetic, cause i already startet to play it out) Situation:
some of your friends and you, want to play Vanilla parts of WoW again, using only Vanilla-Gear (no BC/WoTLK/Heirloom-Items, Enchants and most likely without Glyphs [not clear bout this one, a pure WoW-Account allows you to learn scribe and use Glyphs], talents are free to choose) und with Level capped at 60. More to it, you may even use a new fresh WoW-Account (without addons even being installed). Well most of your friends are actually already started (DDs of course and mostly "pures") and thus you and one other slowpoke are to play Priest and Warrior as... well Healer and Tank. Showing your will to sacrifice, you choose to play the Priest. Being slow but not stupid you use RAF to catch up.
Now comes the big catch-point - actually... there is no way to play real vanilla, as very many things are already changed to much, especially the good old talent-tree. thus, the question (who wouldn't know). How to specc properly to heal decent at 60? We're talking 'bout very beginning now, so green/blue gear, nothing much.
And to make things at least a bit more faire and interesting - shadow-spec will be appreciated too, i mean, you already have another accout or just a bunch of 80s to sponsor yourself a dual-specc.
p.s.: sorry 'bout bad english, hope it is still understandable.