In conclusion, virtual monies, of which bitcoins seem to be the most perfected specimen up to date, do not allow acting individuals to manage the uncertainty of the future as well as material monies do. They could serve to intermediate exchanges among those who invest in the technology that creates them, stores them, and transfers them. Nevertheless, they could never achieve that degree of universality and flexibility that material monies carry with them by nature. Thus, on the free market, commodity monies, and presumably gold and silver, still have a great comparative advantage.
http://lewrockwell.com/orig14/gertchev1.1.1.html