If you believe some people China and Russia are buying like crazy, gold and silver, I have a professor who's a China specialist who thinks in their case at least it is to do with their upcoming decoupling from a fixed rate dollar exchange. They're getting from both ends, with a fixed exchange the US feds money printing devalues the cash supply of their whole country AND devalues the debt they have bought.
They can settle major deals for everything in yuan at the moment because x yuan = y dollars, they still want to be able to settle contacts in yuan when x yuan = z dollars where z is determined by whatever the hell the market thinks...The market being fickle they're making sure they have their gold and silver reserve ducks in a row so the market doesn't short them six ways from Sunday the day they make it happen.
Interesting times we live in. I don't think there will be some overnight end to the USD as the world currency but I think things could start to return to the days of pre euro, things being sold and negotiated in all different currencies. Euro, yuan, dollar... things are going to get a lot more complicated and interesting.
When everybody sees that some of the bigger economies are using silver to back their currencies, even as a minor adjunct to gold, I think it bodes very well.
Even if that's all speculation that comes to nothing you can't deny the east has a mad apetite for PM, I think silver is a bargain in the mid term.