Spectacularly fantastic, and distressingly real, this is the world of the now as few can even approach understanding it. I think, though, that the singularity type catastrophes will probably come unannounced, and unknown to any but the inventors of these, to most, incomprehensible technological developments.

It is possible that the grey goo, nano converter, that will soon consume all matter within it's reach, has already eaten it's inventor, and is presently creating more of itself from the contents of the garage, in which it was brought into being. Then again, this may not be what happens at all. There are nearly an infinite number of other paths to extinction, and only a few which might lead us to a future more desirable than unending silence.

In relevance to the DARPA lecture video, further reading, John D. Lilly's 'Programming and metaprogramming in the human biocomputer'. This is from almost 50 years ago. Imagine what has been invented since.
https://web-beta.archive.org/web/20141229092108/http://files.shroomery.org/cms/biocomputer.pdf

The comments in the video on prions, neural dust, and also hyper game theory were excellent. The time travel comments I find less useful. I do not think travel into the past is a possibility. The rest is relative time distortion, causing time stream divergence.

Many find this knowledge to be fearful in nature. There is much that can be done for the individual to arm their self with the knowledge and preparation to create incentive in others to practice restraint. Knowledge and preparation are the sources of individual empowerment.