Mar 3rd 2009 6:13PM Shadow Affinity now gives the priest 5% of his base mana when his Shadow Word: Pain or Vampiric Touch spells are dispelled.
Remember that it's 5% per rank, so it goes up to 15%. Think you forgot that for a moment. :)
Feb 2nd 2009 1:56AM "Hit rating: For the most part, a healing Priest will not need hit rating. If you intend to do damage in your spare time (as Shadow or otherwise), know that the hit cap is ~237 after every possible raid buff (including having a Draenei in your party)."
1% hit = 26.23 hit rating at level 80.
Which means that even with a Draenei in your party and your own hit buffs (6%) you still need 265 hit rating to get 17%.