Some factions are always trying to get rid of paper money because it wears out so fast.Most people however, don't want to lug around heavy coins.There are numerous reasons why a debit card only system isn't likely in the near future.Add the expense of pennies costing more than a penny to make to the mix.
Perhaps plastic coins and bills could be produced.They would last a long time.They would be light and cheap to make.Another option might be cloth currency.