Simply, but not suddenly. The structure and support surrounding current tangible currencies are backed by so much more security that its almost hard to imagine it's extinction. Even though, I foresee multitudes of possibilities for cryptocurrencies that it may affect value of physical money. The aesthetics of physical money is appealing--especially to individuals uncomfortable and unfamiliar to modern forms of currency. That being said, until the majority becomes more aware of cryptocurrency's abilities/possibilities, don't throw your bi-fold wallets just yet. Cash isn't going away anytime soon.