Volatility can be a major concern with Bitcoin. Look at the exchange rates during the past 24-hours. In BTC-e, it hit $880 after going up to $1,100. Volatility of almost 20% in a single day. With gold, the maximum volatility is in the range of 2-3%.
It is just the ups and downs because of the sales on bitcoins on the exchanges. If people will continue to use bitcoin as their normal currency and will not throw their coins to exchanges then it will not happen which happened today and you will see that within a few days it will start rising again and expert traders are actively buying bitcoins today when they saw the price at lower value.
I expect that to happen, as an investor our focus should be the future of bitcoin and since the price is dropping now, maybe we take some time to buy. It's an opportunity we do not need to miss.