I suspect a lot of the thinking of replacing humans is driven a lot by the nerd scifi facination with the Singularity, but if a lot of the hype fails to materialize after billions of dollars have been poured into AI there could be an over-correction by the market that would take away funding from even useful AI research.
I hope we'll hear less of AI replacing X, and more of AI enhancing X, where X is radiologists, programmers, artists etc.