Blizzard updated their official forums with a notice that said that the Hunter decks have become “increasingly more dominant and are doing better than we are comfortable across many levels of play.” It is not a huge update actually its just one card “Unleash the Hounds,” which grants the Hunter a charged hound for every enemy minion on the board, now costs three mana instead of two.
“Over the last few months, we have seen hundreds of different decks do well in game depending on many different factors. Our community is incredibly creative, and we’ve seen players constantly trying out new things and coming up with new strategies to counter whatever decks they have trouble with.
At the very highest levels of play there are a lot of different decks performing well, and the decks at the top change from week to week. Since we’ve seen many cards and deck types in the current state of the game rise and fall as players adapt, we did not want to change Unleash the Hounds immediately. However, Hunter decks have become increasingly more dominant and are doing better than we are comfortable across many levels of play.
We do like the idea of decks that have a really big turn and pull off a sweet combo, but when playing against Hunter decks, you may feel punished too much for playing minions. Playing minions is one of the key, fun pieces of the overall Hearthstone puzzle, and feeling like your options are limited by the opponent creates a play experience that may not be particularly enjoyable.
We take any balance changes very seriously, and we will continue to hold true to our stance that we plan on only making changes to cards if we feel it is completely necessary. After much consideration we have decided to increase the mana cost of Unleash the Hounds to 3. This change should make the card more fun to play against while still allowing for some big plays.”