Stanwell, the Doble Model E Steamer is still a very viable design with a bit of modern technology input. Even the existing Dobles are marvels of engineering, and very efficient. Maybe if Ab Doble had dabbled in helicopters, we just might have had steam-powered choppers today!
I have little doubt that we are in the age when electric power will become very viable in many fields, but perhaps hybrid power will be the winner in the near-term. After all, the actual HP requirement for a lot of steady motion is relatively low, and IC engines waste a lot of power and energy by running at near full-power output when that full power is not actually required.