Not going to happen. South Korea is willing to give up some privacy for protection (which has worked out quite well for them) but they still have rights that just will not be infringed. If anything could be said about SK restricting access to sites X and Y would be foreigners' access to websites (creating sites where Korean citizens have exclusive access). Many games have their online games exclusive to South Korean residence to help reduce lag on their servers.
SK wouldn't even have considered this ban at all if it wasn't such a serious problem in SK. In South Korea, it's considered normal to go hang out at PC-bangs with friends and just game (where as in America, it's normal to grab a group of friends and go hang out at a mall and what not).
This also only applies specifically to the PC platform. Services like X-Box LIVE and PSN won't be affected at all (then again, they're not as popular as PC gaming is in Korea).
