If Governments continue with their policies of fiscal easing (printing money without the backing of any kind of security - gold, earnings etc) then each unit of currency for that country is effectively devalued.
When currency is devalued the amount of value that can be purchased with the currency is lowered (once it is seen to have a lower value).
The amount of specie money (gold, silver) that can be bought with the revalued currency (in absolute terms) is lowered.
One can judge the amount of revaluation of a currency (paper or fiat money) by the new amount of specie than can be purchased with one unit of the paper money.
Gold will increase in cost (the amount of paper money that must be spent to purchase a set amount of the metal) as long as it is understood that paper money is not at an equivalent value.
All this is down to investor sentiment.
If investors are stockpiling gold then the price will increase until Governments begin to redress the situation of specie against fiat money. To do this they must themselves back their currency with enough gold reserves to alleviate any discrepancy.
The latest calculation I have seen shows that the US Dollar is covered by just 4 cents worth of specie (gold) and that was before the latest round of easing (printing of more US Dollars).
Usually I would be concerned when investors all start to pile into the market (herd mentality) but in this case I see no indication from the futures markets that gold (or silver for that matter) has a large downside. The indications for me give a pointer to gold reaching an upper limit (whatever that may be) but will not plummet.
Since silver has not reached it's historic 16:1 ratio with gold, my suggestion is that silver should be purchased. This is due to the fact that silver is used up at a greater rate than gold in industrial processes and that there is probably less silver available to the marketplace than gold.