Season 2 of ranked play in Hearthstone
will come to a conclusion
at the end of this month. The reward for participation in season 2 is the Black Temple-themed card back, seen above. You only need to hit rank 20 before June 1 to earn the skin, a relatively easy feat for most players -- losses don't cause you to lose ranking until you've surpassed rank 20.
The top players of the season may qualify to compete in the Americas Qualifier Tournament
, the winners of which will move on to compete at BlizzCon. The full qualification details can be found on Battle.net