I think that the current responses aim too low.

Isomorph is really cool, but it's a "next 5 years" (or not) – not 25 years.

The future will be declarative. It'll allow voice input, possibly as the primary modality. Objects and functions will be passe.

IOW, describe what you want the program to do, then we'll refine (i.e., sculpt the details together).