Overall I think Wikileaks is a good thing. The more that those in positions of power and authority believe that any abuse will be exposed the better for all of us.
From what we have seen of the latest releases so far most of it is just a bit embarrassing and generally confirmed what most people suspected. That there isn't peace and goodwill throughout the Middle East brotherhood, for example, and some countries want Iran's nuclear sites bombed is no great surprise. What some US Ambassador to nowhere thinks of Prince Andrew is amusing tittle tattle but no real threat in the great scheme of things.
However, the disclosure of talks between China and the US over what to do about North Korea doesn't fall in to those categories and is dangerous. China is a country that is more sensitive to criticism than most. That doesn't mean that we should censure them for human rights and other abuses, for not allowing democracy and liberty and its many other misdemeanors. However, when we can get them to work with us on tricky foreign policies, such as trying to bring peace and stability to one of the world's most dangerous regions we should be sensitive to their position.
As a friend of North Korea, China was in a special position to help bring about relatively peaceful change. Even if North Korea believed privately that China was willing to work with the US and cede them to South Korean control now it is public it is likely to be even more resistant and and remain capriciously dangerous.
Wikileaks should remember that just because it can, it doesn't mean it should.