Here's the article I read awhile back concerning the satire, although it's not just in the lyrics. The video's important to it as well.
Gangnam Style satirizes a subset of korean culture.
The article mentions that the satire is indeed gentle and nowhere near as subversive as you'd expect from artists here in the states or England. At the same time though, Korea is very different and even this level of satire is something to take note of, particularly because of how popular the video's become. I remember seeing a video of Psy himself mentioning some of these points. If I can find it again I'll link it in here.