Sony Suspending PSN only in South Korea though
The law is known as the Game Industry Promotion Act. Its main goal is to tackle the problem of excessive games usage amongst some sections of the Korean public. Sony have taken the decision to suspend the Network after they realisation they do not have enough time to change the registration process before the law is instated. The Network will be up once changes have been make.
This only effects South Korea network users. The Network for the rest of the world is unaffected.