New York Time's coverage of recent developments on AI seem to suggest that we could be at the base of a new dynamic of growth.
This is IBM's supercomputer playing Jeopardy!
and something more recent – a computer learning language by itself
then.. an AI mimicking empathy and emotions…
and Jaron Lanier's take on this
I would classify AI under a category of "existential" issues since any development in this front would post existential issues to the question of being human. The other example of an existential issue would be genomics and synthetic biology, since that again, challenges our widely held notions of our biological make-up. And nanotech, in affecting our notions of physical reality which remains involate in a common-sense way.
Then again, AI could be a DUD field for the next 50 years, especially since the past 50 years also held promises of exponential development of AI that never came into fruition. I guess this could be opinion I might come to regret in the near future, but for now, the series of NYT does seem rather serious.