The notion of national currencies and fiat money is central to modern economies and government financing. I can't see a world in the foreseeable future, where sovereign nation states give up the control over what currency must be used for conducting its business.
Bitcoin transactions, unlike credit card purchases, are irreversible. If you buy merchandise with bitcoins and the merchant fails to deliver, that money is now securely in his hands. There will be no third party company to go to bat for you