Computer games are a particularly good example. The graphics of the game are copyrightable as is the story. But not the gameplay. All the thousands of first person shooters out there don't pay royalties to the creators of Wolfenstein 3D. With advanced artificial intelligence it should be possible for the AI to analyse a game, understand the gameplay, and then create a new game that is sufficiently different in graphics and plot, but nonetheless captures idea. And given its the AI doing the implementation in the first place, what value then is there to the human coming up with the novel gameplay mechanic? Not much. There are cheaper clones within minutes of release.
To a lesser, but still significant, extent the same is true of movies and books. The plot can be analysed and an expression thereof created.
What does this tell us?
In some ways it suggests that copyright is somewhat strange: it values expression (implementation) more than ideas. And yet it is ideas that seem to me to be what advances us as a species. Someone could take the idea expressed in this blog post and, using different words express it themselves in a revenue-generating medium, and I would have no recourse against that person profiting from my idea (as an aside I have not done the necessary research to confirm this is an original idea, but I can confirm it is independent).
The other thing that this expected future suggests is that copyright will either be extended in some way to ideas, or will lessen in significance as automation of expression becomes feasible.