Blizzard is selling a new mage skin for the World Wide Fund for Nature. Heathstone users recently found that the next hero to be adapted into the a skin will Khadgar, Medviah's apprentice. The source is was found on the Apple store and indicates that you will only be allowed to purchase the new hero skin through ios devices. According to the page, the skin will also be only be sold for a limited time. The source says that it will stop selling the skin on April 24th PDT. That's a really short amount of time considering that today is April 14th.
No word yet has been about the price. But a screenshot from the Singapore store suggests that it could around $5-$7 if you convert Singapore dollars to American dollars