A new developer blog post on Battle.net by Blizzard's Dean Ayala has revealed that Hearthstone has a balance problem and measures are being taken to fix it.
The solution, it seems, is to remove both cards with low power and the big, game-changing cards. These cards will be removed from Arena draft in an upcoming patch.
Ayala said Blizzard is also looking for other solutions to create a better balance in Hearthstone's arena such as adding a designer input value to decide how often cards show up in a draft, or drafting by rarity.
The complete list of cards removed from the Arena draft can be found on the blog post, although the Paladin has no changes.