I should complain more about non-priest issues, but with all these changes it's hard to take my focus on things that affect Sthenno directly.
Shadow Word: Death was doing too much damage, and too much damage to the priests casting it, as I mentioned in a recent post. They decided to divide the damage it was doing by four and multiply the damage on low health targets by three to solve this problem.
I wonder if they considered amounts other than 75% to reduce the damage by. There are, after all, lots of numbers between 0 and 75%. They could have, for example, reduced the damage by 20%, or 25%, or even 40%, rather than reducing it so low that the damage per execute time is lower than Mind Flay.
If the damage of a spell, when cast on targets above 25% health, is so terribly low that it's always a dps loss to cast it, then why not only make it castable on targets below 25% health? There are lots of other spells that have that restriction, and it seems to work fine for them. Making it good sub 25% and castable but terrible at 25.01% might not be the best way to handle the spell.
But of course we may end up having to cast it above 25% anyway. Since a talent makes taking damage from it restore 10% of our total mana, it's kind of like Life Tap. It differs from Life Tap in a couple of key ways, of course. For example, has the upside that it does a little bit of damage but the downside that you can't use it between fights or during downtime when there is nothing to shoot. Another difference from Life Tap is that the damage you do to yourself can be prevented to cancel the effect, so if a Discipline priest gets so much as a critical Renew tick then our Life Tap fails. It also has a 12 second cooldown to make sure we can't spend too much of our time doing extremely low damage to the enemies. The cooldown goes away when the enemy is under 25% - that is, there is no cooldown when the spell actually does a ton of damage.
It seems like a number of different people all thought of changes to this spell and all implemented them without thinking about how they actually interacted with one another.
If they want it to be an Execute, they should make it an Execute. If they want it to restore mana, they should make it restore mana. If they want Shadow Priests to do several thousand dps to themselves once the boss gets under 25% health then they should probably just go ahead and rethink what they want. Right now this spell has too many conditions and add-ons, and it needs to be sorted out.