The only difference in BitCoin and the dollar, euro, yen, peso, whatever currency you pick, is that one is centralized and ordained by a government, bitcoin is not.
They both rely on the same exact principles, faith.
A currency, whatever it is, is only worth as much as people believe it is. Right now, people believe it is worth a lot...for god knows what reason.
My comments and posts are simply my opinion. ALWAYS DO YOUR OWN DD.