Khadgar is being handled differently. You can only purchase him on iOS devices. Once you do, he's available for use on any version of the game. He only costs $5, and proceeds go to the World Wildlife Fund (WWF). It's part of the Apps For Earth campaign from Apple and the WWF.
The idea of using in-game purchases to support charities is something I'm happy to see. We gamers will spend money for plenty of shiny things in our games - nice to see some of those proceeds being used for a good cause. It's too bad that I can't participate, having no iOS devices.
I certainly get the concept of doing exclusive deals on a platform basis. It makes sense if you're talking about a game that is only playable on one platform, to try to sell that platform. But when you're talking about a cosmetic add-on, made available solely as a charitable contribution, exclusive deals make little sense. People aren't going to go buy an iPhone or iPad just to get an alternate hero in Hearthstone. Apple does get some good press from the deal, but that would happen even without the platform lock, since their name is on the Apps For Earth campaign itself.
I haven't bought any alternate heroes for Hearthstone yet, and had no plans to do so before this. So being unable to buy Khadgar really doesn't affect me. The WWF donation aspect might have convinced me to do so, though...if I was allowed to. I could donate directly, of course, but that's outside the scope of the Hearthstone promotion. Besides, anyone likely to donate directly to the WWF has probably already done so without needing an online game to get involved.
Seems to me that limiting this particular purchase to iOS devices is an unnecessarily restrictive choice. The impact of that restriction won't affect Blizzard or Apple, but the Apps For Earth donations to the WWF will be a bit smaller.
