New Global Currency - Seems Perfectly Reasonable to KillerB

A few months ago when China and Russia began suggesting that the US Dollar perhaps isn't the best reserve currency the world could have, people lost their shit. Not just nut jobs like (macro-economic genius) Glenn Beck, but other, respectable American folks. Since then the drumbeat has grown a bit louder, and today the UN has issued a report suggesting that.....WAIT FOR IT....the US Dollar perhaps isn't the best reserve currency the world could have.

I understand why policymakers and Senators and publicly accountable officials would be against this, and I understand it would be a blow to the US economically, emotionally, etc. But isn't the core idea pretty sound? That the world should not be trading almost exclusively in the currency of one country, whose GDP accounts for just 23% of world GDP, seems like a pretty fair point to me.

Doesn't the argument of diversification hold here too?

Someone set me straight.