I would distinguish between the anti-US political dollar...

I would distinguish between the anti-US political dollar rejections by some of the South American nutjobs, and the willingness of less hostile nations to either engage in or initiate the actions.

For example, previously I'm sure the SA loops had asked China to renounce dollar use, to which the Chinese would have politely declined. Now, however, they are making a significant statement. However, that statement is not a "We hate the USA and all it stands for." It's more of an economic warning that, "You hold reserve currency status because we all agree to it, however we can do without you. Behave responsibly and don't push us too far."

It's this second element which is so dangerous to US hegemony. I'm sure that even after this Chinese/Argentine announcment, it will already have many countries and commentators thinking, "Well, you know, maybe it's not such a big deal after all. Maybe its just a single, further step in our existing bilateral trade deals...."