While there was and is a certain value in releasing secret information from the government that a war is going poorly and the public is being lied to, I have to agree with Steven Benen about the latest wikileaks dump:
I would, however, like to know more about the motivations of the leaker (or leakers). Revealing secrets about crimes, abuses, and corruption obviously serves a larger good — it shines a light on wrongdoing, leading (hopefully) to accountability, while creating an incentive for officials to play by the rules. Leaking diplomatic cables, however, is harder to understand — the point seems to be to undermine American foreign policy, just for the sake of undermining American foreign policy. The role of whistleblowers has real value; dumping raw, secret diplomatic correspondence appears to be an exercise in pettiness and spite.
Checking abuses of power is one thing. Publishing diplomatic cables where someone calls Silvio Berlusconi a dick is something altogether different. Like sausage making, diplomacy and negotiations are not always a pretty thing.