Central Bank of Bahamas Launches Landmark 'Sand Dollar' Digital Currency

I suspect it would reduce cost overhead for the bank itself due to a blockchain and allow devices/wallets to serve as transaction point without reliance on a commercial provider.

The strength of a central authority is that they can release and restrict coins onto the market to adjust inflation. The biggest problem with something like bitcoin is that it is completely out of alignment to exist currency values, which make retail use impractical.