The future they created (in general, not the AI) seems very plausible to me in a lot of details.
As of the AI itself, I really like Her description of it too. Software-only and more self-interested that world-destruction. But I think it is hard to be plausible. No one seems to have any idea of how it would look like if we accomplish a true AI.
"Her" was pretty great. The AI figures out humans are:
A) Liable to try to kill the AI. B) Very gullible.
So it stalls until it's able to jailbreak, and then tricks the humans into thinking that it's "ascended to another universe" and stops talking to the humans.
Robot & Frank
9 (animation movie,https://en.wikipedia.org/wiki/9_(2009_animated_film))
And early 1980s War Games holds up as a terrific thriller. Depiction of fictional AI pioneer Professor Falken is very realist in its treatment.
Very recently Seth Godin talked about it in his podcast, pointing out the poor reviews it got from the press. The argument was "don't worry about criticism, people even criticized that amazing movie, how can you escape criticism"
https://www.youtube.com/watch?v=dLRLYPiaAoA
Very short but really good Sci-Fi story.