A major advantage of this design is that it uses no platinum which is one of the major cost drivers in fuel cell construction. The initial prototypes are generating enough electricity to power small electronic devices. The new design isn't yet commercially viable, but they have made tremendous progress in developing enzymes that are resistant to the presence of oxygen. The biofuel cell is also not affected by the presence of carbon monoxide which when present in platinum catalyst fuel cells poisons the cell. More information is available in the press release at the Read link.
[Source: American Chemical Society]