I use to tank and I remember tanking HM maloriak I use to get a buff from our Priest that said something along the lines of (30% more heals given by priest) and I remember or at least thinking that it stays with me the entire time, though I could be wrong. this was during 4.0.6 but since then I've quit that guild and am on my Shaman and I have a newer priest that doesn't know of that.