Gold could certainly continue to increase in value in coming years for two primary reasons:
1) Gold production is declining over time. We may have reached peak gold where demand is outstripping supply, which causes the price of gold to increase.
2) Government debt in the U.S. and Europe may cause continued curency debasing, which makes gold a compelling hard asset to own.
I wrote an article about this at: http://www.stockrockandroll.com/?s=gold+bull+run