Wikileaks is, according to Wikipedia (the free online dictionary), an "international new media non-profit organization that publishes submissions of otherwise unavailable documents from anonymous news sources and leaks". So basically WikiLeaks takes leads or stories or documents from anyone, does their best to do a fair anonymizing process, check the source credibility (truthfulness of the subject matter), and publishes the document.
Most of people probably at this stage, in 2010, skim the headlines; reading quickly something about Assange, and rush on to more important matters. But wait a second - isn't WikiLeaks important? Utterly so. It is revolutionary in perhaps the electronic mechanisms and finesse that has been put to ensure it will stay online, evade possible denial of service -attacks (DOS) and keep publishing.
Today I read (or actually listened to) some videos on Youtube about the hacking history of Julian Assange. He has had a fairly colorful and bit-active life, also doing some practical pranks on space missions. The Melbourne-based group had this posted on a mission control panel on the launch date of a Galileo probe: