There's one tweet from the the blog a few days ago (astral something?) that sums up my view of the problem pretty well.

General population: How will AI get to the point where it destroys humanity?

Yudkowsky: [insert some complicated argument about instrumented convergence and deception]

The government: because we told you to.

Again, not saying that AI is useless or anything. Just that we're more likely to cause our own downfall with weaker AI, than some abstract super AGI. The bar for mass destruction and oppression is lower than the bar for what we typically think of as intelligence for the benefit for humanity ( with the right systems in place, current AI systems are more than enough to get the job done - hence why the Pentagon wants it so bad...)