I've been saying it for 15 years, along with everyone better learn to speak Chinese.
The days of America as a world economic super power is gone. When you have more than $60,000,000,000,000 (60 trillion) in unfunded debts, liabilities, and obligations, with no way to actually fund them, you are definitely not in good standing. You just cannot hide from the realities of math.
Other than the (possible) change of tender to be used (no real difference on the skin from Australia moving from Pounds/Shillings to Dollars/Cents), what are the real further implications that could come of this? Go nuts, as wild and unlikely as possible to the more conservative and likely possibilities.
There's been talk of a few ideas the Chinese are floating around. Yuan might be the choice but I'm pretty sure the dollar will be f'd in the long run. You can't print currency (especially a reserve currency) without repercussions.