Ideally, the world of art should be available to as many people as possible with as few technical impediments as possible. Until all impediments have been removed there is a way to improve engines, if not presently, then in the future.
That is to say that "artists", animators, programmers, musicians, actors, voice actors, and writers should be made as obsolete as possible.
Until anyone can imagine a world and/or story within that world and have it come to life with a mere thought, then there is much more work to do on engines and the tools we use to express ourselves on the various canvases.
The goal of writing a book is not the words on the page but that the message is transmitted faithfully from author to reader and the same is true of every other medium. We are impeded by the fact we do not have tools to make these mediums available to everyone. To make these tools should always be the end goal of tool makers.
As to specific technologies and ideas that could be improved upon is perhaps a dynamic interpretive model creator and animator which would take input from the person and interpret it into what is desired... Adaptive AI constrained to certain knowledge and personality settings... Procedural music generation... Voice Synthesis technologies... Common Spoken Word conversion to computer languages... True procedural world generation and localized predictive procedural generation of language, animals, civilizations, etc
No offense to you guys, but skimming what you guys have said, kinda not evolutionary or revolutionary to engines. All you are talking about is faster CPUs in reality as that is all most of that is. It's not that we don't know how to do it, but that we don't have enough power in the average PC to do it at the level we'd like to do it. It's either a new trick or more power, but that's nothing but a bigger hammer, not a better hammer. True, sometimes a bigger hammer is a better hammer, but when I think of making a better tool it's not very impressive to say make it sharper, make it bigger, make it harder. Those aren't new grounds in technology. They may result from new grounds in other technologies, but they, in themselves, are not new technology. So when someone asks me questions like this, I think what is the goal of the tool and what would make getting to that goal possible for as many people as possible.