I can't see paper disappearing completely... let's face it imagine that the power goes out not to mention something much worse like a earth quake or war. What would you reach for in one of these situations? Granted fiat might loose its trust in a war but if the lights go out what should you use as a medium of exchange? Metals is one option I can come to think of but that seems quite far fetched (at the moment) looking at it from a centralbankers point of view... but hey I might be wrong...