I think Digby has written the best piece on why Wikileaks is important and what stance progressives should hold towards it. This passage is of note:

It’s true that much of what’s been revealed in the last year has pertained to US foreign policy, but the US is the world’s superpower, spending more on its military than the rest of the world combined, has more global interests and more connections. It’s natural that it would be a primary subject for such revelations. But that doesn’t mean that Wikileaks is only interested in the US or is working on behalf of others to bring it down. Remember, it’s certain Americans who have felt compelled to reveal these secrets about out country. Why the messenger should be shot is beyond me.

Also:

People feel very strongly about this on all sides and that’s fine. But I do think that there is one thing we should all agree on: the appalling open calls for Julian Assange’s assassination are barbaric authoritarianism at its worst. (The obvious attempt to smear him as a sexual predator for alleged condom failure fall into the same category.) The man put some documents on the internet and there is a vigorous global debate going on about it. If there was ever a case for public servants and the media (which should all clearly be on the side of Wikileaks, in my opinion) to be circumspect in their language it’s in this case. I’m astonished that these calls for murder are so casually accepted. (But then, we are living in a country in which torture is accepted, so I’m probably foolish to keep clinging to these silly notions about civilized, democratic behavior.)

PFC Manning is known to have leaked documents to Assange. He has been arrested and faces court martial and a very long jail term if convicted.  Wikileaks is just a messenger and not the only one (eg., the Guardian provided the New York Times with this round of documents the US paper of record has reported on). Given that the leaks are in no ways exclusively damaging to the US, but most other major governments of the world, it’s really hard for me to get the hysteria around Wikileaks as being particularly anti-American. Throw in that there are as of yet no documented cases of people being hurt or killed as a result of the leaks and I think this is not much more than powerful people (mostly governments) coming together to defend themselves from facing public scrutiny. That the reaction from Western governments and the Chinese government is functionally the same is both disturbing and telling of the commonalities between threatened elite power structures, regardless of what governmental system they exist in.