The only buff I know about slayers that one of their talents will be removed and will be a passive instead. The passive will shorten the CD duration of a skill or two. But as the text says, it's "planned". Or at least I didn't hear about it actually implemented.
Display MorePlanned
Improve Slayer damage capability
Slayers had issues of damage disparity due to talents, so on September, [Propulsion] talents are planned to become passive and new talents will be introduced.
[Propulsion] Eviscerate: critical damage reduces Cooldown of Measured Slice
[Propulsion] Whirlwind: critical damage reduces Cooldown of Measured Slice
EDIT: That was in July.
Tomorrow's KTera patch says:
2. Balance Adjustments for Certain Classes and Skills - Balance adjustments will be applied to certain skills for Slayer, Priest, Mystic, Warrior
I haven't seen the details about these adjustments yet. We'll see that tomorrow I suppose. x)