The ongoing Wikileaks phenomenon includes so many elements that are obviously good, so many that are obviously bad, and so many that simply are, as huge-scale technological forces of nature, that I am suspicious of any axiomatic "he's a hero" or "he's a villain" judgment about Julian Assange and his associates.
I mention this as a segue to the very valuable compilation that the Atlantic's Alexis Madrigal posted last night, summarizing and linking to a broad range of the most informed and well-argued attempts to "think about Wikileaks." To spend even ten minutes considering the range of views is to get an idea of how long it will be before we fully comprehend the goods and bads of the new balance of power among governments, "normal" journalists, citizens, hackers, corporations, humanitarian organizations, criminal or terrorist organizations, stateless alliances, and everyone else.
I am particularly glad that Alexis included a link to "Ten Theses on Wikileaks," by Geert Lovink and Patrice Riemens, which was published last summer after the initial leaks of the "Afghan War Logs" but which applies well to the later larger releases too. I'd suggest starting there, but Alexis points to many other valuable analyses too.