The death of Kim Jong-nam and Jang Song Thaek gave a heavy blow to china.  
That means all pro-china political influences have been purged and expelled.  Kim Jong-un will definately defy china with a "so what" attitude, as always he has been.

It would be safer for Kim Jong-nam to stay in Beijing and Macau, as china provides protection to him by upgrading the standards of his personal security.  But his "playboy's" propensity defies the personal dangers he faced, which made the story today.

Kim Jong-nan used to be favoured by his father Kim Jong-il and was appointed as a potential successor.  He fell out of favour and was seen as something of a political lightweight after he was embarrassingly detained at a Tokyo airport, trying to enter Japan to visit Disneyland on a false Dominican Republic passport.  Kim Jong-nam and his family afterwards lived in virtual exile in Macau, Singapore and China.

Kim Jong-nan used to talk to the reporters that:"Anyone with normal thinking would find it difficult to tolerate three generations of hereditary succession."

Both Kim Jong-nam and Jang Song Thaek, who was purged and executed by Kim Jong-un, were pro-chinese.  China prefers Kim Jong-nam to Kim Jong-un.  That describes the current relationships between China and N.Korea.

So, Kim Jong-un should be "happy now".

Kim Jong-un was probably behind the assassination in order to consolidate his power.