The ruble will never replace the dollar. The Chinese yuan, maybe, but not the ruble.
The larger ones are arranging direct trade between themselves using their own currencies as the article points out regarding Russia and China.
If this extends to the EURO, and it will do so in due time, then the US dollar will no longer be the currency of choice or the mandated currency globally.
It is estimated by some experts that the quality of life that US citizens have enjoyed via the ability to print money when needed will decline by at least 25 to 30 percent. That estimate is reasonable, I think, based on our debt and the fact that without the ability to print as we have been doing, and stacking the money in others state banks, we will be forced to devalue at a time when inflation is the primary financial problem.
The only thing holding us up right now is the plain fact that we are bad, but others are worse.
That situation is changing.