It's a way of "giving something back" to such a "supportive and skilled community" unlike any other. No such love for western gamers though.
This offer was unveiled at a recent StarCraft II event in Seoul. The deal remains active as long as the World of Warcraft subscription does. Given the huge popularity of StarCraft in the nation this will certainly help drive up WoW subs.
In South Korean StarCraft II can be bought outright or a monthly pass, or even a 24 hour one, can be bought unlocking the game for a period of time to play. This method is only available in the e-sports loving nation.
Should we US/EU Blizz fans be given the same degree of courtesy? We pay for WoW too!