In addition to the big list of class and class tier set changes from the PTR notes today, Blizzard also detailed upcoming changes for a future build in a separate post.

Upcoming Set Changes (Source)

These changes will not be in this week’s PTR deploy, but will be in a for a future PTR build.

Holy Priest redesign

(2) Set Bonus: When you cast Prayer of Mending, there is a 35% chance its effect is duplicated to another ally.

(4) Set Bonus: When Prayer of Mending jumps or expires, it increases the damage and healing of your next Holy Word by 4%, stacking up to 15 times.

Developers’ Note: We’re making this change to ensure that Holy’s 2 piece bonus remains in line with the other healer set bonuses, regardless of target count and randomness. This iteration should still offer strong value to the Holy priest kit and we’ll continue to monitor its performance to ensure it does.

Outlaw Rogue:

(4) Set Bonus: Between the Eyes grants 5% Agility for 15s. (down from 7%)