There is a quite good reason why Korea will always have the troubles to promote itself. Factions. It is still prevalent factor to country's inability to promote its cultural heritage as aggressively and wide as all the neighbours. There is always someone who says "but why your agency not mine?" and dampens down any efforts. I remember the Olympics in Seoul, and I remember there was nothing on Korea anywhere back then. Oh well, that pattern is not totally unfamiliar to me, in my country, we have exactly the same actions.
But then, if PSY is considered as Korea's brand, then maybe every viral video should be the symbol of the country it comes from? It's called "viral" for some reasons.