This is an interesting question and taking it from the "pragmatic" viewpoint, I would say Python. Python is a language I tried to actually drop in favor of fancier languages, but it is just too productive. A lot of AI programming is experiments, and it lends itself toward something like Python.
If I had to pick what I would hope the language of the future would be, it would look something like F# or Swift for AI. Swift could be a stealth language that could take market share from Python, not sure, but it is fun to use.