This is an interesting blog post refuting my point that Wikileaks hasn't done any damage. Essentially, GG is arguing that the leaks break down diplomacy, and will be more inclined to use military action (instead of diplomacy) in the future.
He goes on to further argue that the people for it believe these documents will only affect the US Government, until they begin leaking personal documents.
The slippery slope argument makes sense to a certain degree, but I don't imagine I'm a part of any classified documents. Yet.