I've been gone from WoW since March, however I am a nerd and I keep an eye on things. So I'mma rant.
Holy Mastery.
The changes being implemented were recommended while Cataclysm was in closed Beta. Mastery as a stat in 4.1 was less viable than Mp5 in Tier 7. 7 months of "Live" to get a change is a long time for something that was brought up while content was in development. Even with current changes haste will still trump the other secondary stats.
Light of Dawn
In beta it was too strong, so it was nerfed. The BoL part was kept, though they later threatened to take it away. The overall healing is solid when you factor the beacon effect on the tank but the actual raid healing aspect of it is low due to it being balanced around the BoL transfer. When they tried to remove the transfer the top end community was all for it as long as they boosted the raid heal aspect of it to compensate, this didn't happen which was a shame.
Also it's a situational raid heal based on a secondary resource which is currently doesn't have the smoothest flow to -it (Holy Power).
-
Holy Radiance
Instant cast but doesn't work with mastery and on an excessive CD. Blizzard has hinted at shifting it to a cast and some major changes to how it works. Which is a ray of hope, since two situational raid heals that are almost contradictory in terms of the positioning they need you to take in relation to the raid is just bad design.
Holy Power/Tower of Radiance/Holy Shock
HL working with ToR was OP. It needed to be changed, however the change was knee jerk and the talent as it now stands is cumbersome depending on the fight mechanic entirely worth skipping. It needs a redesign to make generation of holy power feel smoother and more natural, but that isn't going to happen anytime soon.
Holy Shock was nerfed in Beta because HS + WoG spam was powerful in an early build. It stayed nerfed, as it stands right now if it was not for the clunky mechanics for generating HP and a semi broken ToR it actually doesn't pay to waste a gcd using HS due to the size of the heal.
/Rant
Overall that disconnect between the devs and the players, the poor design and layout of the class and healing in general in Cata is probably the reason you won't see anymore WoW rants from me. So I guess someone who hated me for all my T7 gripes owes the Devs a beer.