https://playhearthstone.com/en-us/blog/21758133
Naga Sea Witch – Will cost 8 mana. (Up from 5)
Spiteful Summoner – Will cost 7 mana. (Up from 6)
Dark Pact – Will restore 4 Health. (Down from 8)
Possessed Lackey – Will cost 6 mana. (Up from 5)
Call to Arms – Will cost 5 mana. (Up from 4)
The Caverns Below – The quest reward, Crystal Core, will read: For the rest of the game, your minions are 4/4. (Down from 5/5)
Once the changes are in effect(after the HCT playoffs), there will be a period of time where the cards will have full dust refunds(yes, you should Disenchant all these cards then)