I'm pleased to read that the general consensus is that there will be future locomotives with albeit alternative/multiple power sources. I'm happy to have been proven a bit too pessimistic with this topic. As you know, I am a fervent supporter of freight being transported en masse by rail to hubs, where from there, road distribution can connect the last part of the journey (from hub to supermarket etc).
Interesting to read about the shunters. It seems there isn't much of a requirement for them these days, as I have witnessed their decline due to fixed formations or other methods of marshalling, not to mention the decline of marshalling yards specifically up here in Scotland.