The media is tittering with excitement that Google executive chairman Eric Schmidt's visit to North Korea must result in the country opening up the Internet to the rest of the world. Their hope is vanity.
The problem for North Korea's leader is that he (and his father and grandfather) have created a god-like myth about themselves, called Juche. According to the myth, Dear Leader is so amazing that he himself designed all things in North Korea (buildings, dams, etc), that he made North Korea fully self-sufficient, and so he must be worshiped like a god -- even by tourists, who are brought on their first day to the enormous plaza featuring statues of Dear Leaders, and told by their minders to bow.
To open North Korea to the world through the Internet would allow citizens to see that their so-called Dear Leader has feet of clay. When you are a dictator, you don't want to lose power by allowing your followers to know the truth. So, the Internet must remain closed to maintain the lie of Juche (c.f. Iran).
The current North Korean policy is to bring in some expertise for the families of the ruling class living in Pyongyang, such as English and limited amounts of technology, while outside the capital city the bulk of the population is left to live in darkness and near-starvation.