In a thread on Twitter this afternoon, Hearthstone Game Designer, Alec Dawson, talked about the upcoming changes. Here is what he had to say.

Quote From Alec Dawson

Balance changes are coming early next week! For this balance patch, we were looking at three main categories: Demon Hunter, mana reduction, and setting up classes for the remainder of the year.

Demon Hunter is still the number one force in the meta and has a great role in determining whether or not a deck is competitive on the ladder. The changes to Kayn Sunfury and [Hearthstone Card (Metamorphasis) Not Found] are slight adjustments focused on Demon Hunter's reach and ability to control the board.

Warglaives of Azzinoth was one of the best cards in the class, especially in aggressive decks. In the future, we want to be able to push Demon Hunter into archetypes other than aggro/tempo.

As for mana reduction, we want to lessen some of the giant swings currently in the game.

Swing turns will still be present in Hearthstone, there's a healthy medium there, but not to the extent of Dragonqueen Alexstrasza or Galakrond Rogue. Dragoncaster moved to 7 mana to make that turn a bit more appropriate as to when it's occurring in the match.

Fungal Fortunes and Corsair Cache were both strong performing cards that limit some of our ability to extend those classes into different spaces later in the year. These changes should make it easier for future archetypes to take shape and be competitive.

Finally, thank you all for the feedback throughout the last few months. We're always listening so keep it coming.