A rise since 2000 is a bit misleading I think, a lot has changed, especially a lot of gold related financial products emerged in that time frame, tradable gold funds, ability to buy gold funds on margin, internet trading, online dealers that sell gold, etc... making it possible for anyone to buy gold with a few clicks of a mouse...
I think good chunk of the gain since 2000 is solely due to the fact that it became easier to buy gold, a change which is unlikely to happen again...
think about yourself, were you investing in gold before 2000?
I would guess no...
a. it was a pretty damn poor investment before then...
b. it was relatively hard to invest in gold