Given the potential downsides are possibly extreme (however unlikely) I'm happy that people are paying attention.
I think a lot of "AI" is hype and hyperbole and largely those people don't worry me that much, its the quiet ones doing fundamental research that worry me a bit more.
You are talking about a breakthrough with a threat level in the same magnitude as nuclear weapons, dinosaur killing asteroids etc.
Personally if I had to put my money down I'd say I wouldn't see a human-level general intelligence in my life time but a self-improving/learning intelligence doesn't have to be human level to be very very dangerous either.
Recommended read:
https://en.wikipedia.org/wiki/Superintelligence:_Paths,_Dang...
In short, it has become political. Suggesting that we should come up with more clear definitions and timelines, or alternately not discuss AI in a way that either wows or scares people is accepted as being "anti-technology," somehow. This is motivated by the high expectations that investors in this space have placed in machine learning tools, and the fear of the overall economy being stuck in proof of concept hell, resulting in a loss of investment.
It's essentially a very sophisticated boiler room.
In any case, I think the key legal problems of current AI and machine learning by extension are related to privacy. We've let such services invade various parts of our lives and we have no legal barriers sufficient to ensure no one's civil rights are violated as a result. So, let's work on those issues before we worry about making the next Colossus or Ultron.