Community Manager Zeriyah posted the latest Hearthstone beta build patch notes which is coming out very soon. No date was provided, but the Tuesday maintenance might be a strong candidate for this patch to be released.
This new patch doesn’t have many changes or additions other than to address current class cards and neutral cards that seem overpowered.
In the case of the mage card: Pyroblast, the game developers wish the mage players to be more interactive with their cards rather than to deal ten damage as the goal to then pyroblast twice to end the game. So the cost of Pyroblast