It makes me really look forward to tech such as Adobe's VOCO (which was a prototype only). It allows you to generate speech based on original content. So you could record x# of voice-acted lines, then use the generator so add more text without needing the actor for modifications, added lines, or original content.
I wonder if the prototype is available to companies. For modders, this would be golden. They could add dialog and voice to characters using the character's original voice, or they could transform to some other voice (think more monstrous goblins speech for example)