I thought I’d point out this post out from the US WoW Priest Forums, as I don’t think it will be seeing a sticky.
Soulcorruptr (smart guy, he’s made some movies, see here) posted his ratings of the four healing classes. They were graded on Talent Trees, PvE, PvP Solo, PvP Battlegrounds, 2v2 Arena, 3v3 Arena, 5v5 Arena, and Fun Factor. A very insightful post, obviously slated toward PvP. However, while it discusses the Holy Paladin, the Resto Druid, the Resto Shaman … it compares them with the Disc Priest. Perhaps he is looking at S3, where Disc will see more play, many of the comments on the post, myself included, think the Holy (Blessed Resilience) priest should have been rated as well. If you look at the S2 arena ratings, there are more holy priests than disc priests in top teams.
In any case, it’s an interesting read, so check it out.
Oh, and for those who are interested, Soulcorruptr has his own forums, mainly focusing on priests and PvP. Check that out, too; he has some great info.