Should Americans be worried that other countries are talking about post-U.S. dollar based economics?

Now France is in on it? I'd read stories about China, Russia, Japan and India and now it seems that France has thrown in? That doesn't really sound right does it? I don't know what's going to happen to the future of the dollar and I'm not an economist but it seems like it wouldn't be a very smart move for China. Since they hold so much of our debt and so many dollar ets, it seems to me (again, not an economist) that it would be in their best interest to keep the dollar as strong as possible and a move like this could, potentially, lead to it's collapse which would make our debts virtually worthless, right?