Hearthpwn

It has a lot of answers, few weaknesses, and a combo that's nearly a OTK from full life.  I worry that it will get even worse with a few of the previewed cards, psychic scream being a large offender.  

They have early game removal, massive board clear, spot removal, Shadow Visions helps ease the Highlander drawback.  It's just a matchup that is incredibly hard to tech against or even build a specific deck to fight.  It's also a large % of what you see in the ladder.  

Quote from V_enom >>

I love Priest and it was always my favorite class (because of the Dragons theme) however i really hate the current Priest because everybody plays either Big or Highlander Priest, both are 100% high roll decks who don´t require much braincells to win (that´s what high roll stands for). It´s just not fun to play against (like most current meta decks).

Because priest has all the answers.

1-  u get controlled early ===> potion of madness

2- you swarm the deck  with low cost minons ===> spirit lash + thalnos or  shadow word horror

3- u play a few value minions ===> shadow word pain and death

4- u play bigger minions ===> dragon fire potion, SR Anduin

5- some luckily dealt damage will be undone ===> greater healing potion, priest of the feast

6- after all of this, his late game dominates you with raza, velen and hero power