Obviously it depends on execution, but if this works, I could see a version of this on commuters or bike-share bikes. Combine the shaft drive with a commuter-style internally geared rear hub, there's potential for lower drivetrain maintenance.
I think it looks cool, but I wonder how it deals with shock, bumps, and vibration. Chains have links, derailleurs have springs. If these things aren't adequately resolved, I don't think we'd see this working for commuters, let alone enthusiasts or professionals.