I think it will continue to rise quite a bit - one can't ignore the ratio of dollars to bitcoins in considering the possibility of bitcoin becoming a widely-used currency, even if it doesn't replace fiat moneys entirely. But probably not to $10,000 per coin, and here's why - because in a free market for money, there will be lots and lots of different moneys. Bitcoin will have to compete with others of its kind, with hard currencies, with labor notes, and other things. I suspect that it will condense around the techier sorts of markets, with some significant overlap into other areas, but not enough to make 21,000,000 bitcoins represent all 40 quadrillion US dollars or however many there are when the dollar finally bites it. I think that gold and silver will be the most widely used money, as they have been for the last 5,000 years of human history, and bitcoin will merely be measured in grams of gold instead of dollars. Its usefulness as a medium of exchange over long distances, however, cannot be duplicated with physical transfers of metal, or even with "warehouse receipts" for the same, which is why I do not expect it to lose in a truly competitive market for currency. (Presuming it becomes easier to buy and sell with time - the whole buying e-currency A which is the only thing that is accepted for e-currency B which is the only damn thing Mt. Gox will accept frankly sucks).