I think the Chinese Govt. will bide their time until the right moment. They have already been unloading USD's in a systematic fashion, just not in large enough amounts to panic anyone. They don't want to start the stampede, that would hurt them a lot to be left "holding the dollar bag." By buying all the hard assets (such as commodities) that they can get their hands on and paying African countries in dollars for all the joint ventures (mining, infrastructure etc.) they have going on there allows them get rid of quite a bit of USD's. China's incursions into Africa were the major reason for the US military forming Africom or whatever it's called. China has a growing influence in Africa and pretty much keeps some of those little African countries floating with their $. The Chinese leadership doesn't strike me as being prone to taking a lot of risks. I think they're more of, to use a boxing term, counter-punchers. Just biding their time hanging around throwing jabs and then just at the right, or worst moment, depending on your point of view,

they'll smack you upside-the-head with a right-cross that knocks you on your a** like Mike Tyson in his prime smacking down the latest chump of the week.
They don't have to do anything really but wait. I think after some more US banks fail and and we hit the next circle around and down the drain could be the moment the Chinese act and say, "well, look at you clowns, we can't hang on to all these dollars anymore all your banks are failing." So they dump dollars on a large scale thereby triggering the exit by everyone else out of dollars. And that would be the headshot to the US economy. Goodnight.
Here is a very interesting list.
http://www.lewrockwell.com/chris/banks/banks.html A list bankers wouldn't want you to see. A list of US banks and their "Texas Ratio."
http://en.wikipedia.org/wiki/Texas_ratio And here is the story explaning what it means.
http://www.lewrockwell.com/blog/lewrw/archives/40739.htmlI see a lot of GA, FL and IL banks ready to go under.
I could be completely wrong about this as a trigger. But I do know that
something will trigger the exit out of dollars. Just a matter of time.