This comes from a conversation I had with a few friends at a new year's get-together. The topic of WikiLeaks somehow came up, so I briefly mentioned how it's good that WikiLeaks is doing what it has done so far, and that because someone within the military leaked the documents (and WikiLeaks just published the already-leaked documents), if it wasn't WikiLeaks, it could have just as easily been a different organization.
They disagreed, saying that though the documents this time around may not have been harmful, that could easily happen with the next round of publication of leaked cables. They also said that for that, Julian Assange should be tried for treason (if such dangerous cables do get leaked).
And you know what? I agree with them on that last point. Although most documents are likely to be relatively innocuous, there are likely to be some cables that do truly threaten our national security, and those should not be published (and if they are, then certainly Assange should at least be tried). (Then again, as Assange is not a US citizen, I'm not sure how that would even work, but that's another story for another day.)
But WikiLeaks will never publish any truly sensitive documents. Why? Two key facts that most major news media leave out are that, for one, of the roughly two million documents WikiLeaks has in its possession, it has only published two thousand, or 0.1%, and all of these published documents have been published by other major news outlets as well (some before WikiLeaks, in fact). The other key fact is that every single document that WikiLeaks publishes is done with the approval of the government (and this includes edits like redactions), so no matter how strongly some members of the government may condemn WikiLeaks and Julian Assange, someone group of people in the government is approving all this (probably in the executive branch/bureaucracy, which explains why the legislators are the ones getting most worked-up), and WikiLeaks will never publish any truly sensitive documents (provided they continue to abide by these procedures).