This same dynamic plays out among world currencies (EUR, GBP, JPY) it is just that you, the individual, living in your own country do not see this market as it is not integral to your daily life. Right now the price is set by supply and demand. There is inheirently fixed and only slowly growing suppy of Bitcoins but more and more people demanding to hold it. More traders are buying it and holding onto it rather than selling it in expectation that even more traders will want to buy.
What you should see is traders and holders of bitcoins starting to leverage their wealth in Bitcoins to buy things they may not have the dollars to purchase. College students on fixed budgets that happen to have lots of Bitcoins from various sources may trade them for computer parts, energy drinks, snacks, etc. When this becomes prevalent the REAL economy of Bitcoins will develop. Bitcoins will become even MORE valuable as they will be in more demand to buy a wider range of goods and services.