The value of Wikileaks is that it makes secrecy more difficult for governments. Period. What Wikileaks publishes is dependent on what is leaked, and so far (in my opinion) Wikileaks has done much to gain credibility as an institution. Notably, it has moved away from journalistic interpretation of the leaked info and has left that to established papers. Instead, it has focused on its role as conduit and trusted intermediary.
Ironically, Wikileaks will enhance the credibility of government in a good way b/c it helps the public view its government as fallible, corrupt, and absurd, all of which help rein in the scope of government action so that what is actually undertaken stands a chance of being accomplished honestly.
Sadly, much of what has been leaked shows simply that the government is putting on a show for the American people and that much of what is kept secret is done so for propaganda reasons, not security reasons.