Excerpt from the video: "Bioethicist Julian Savulescu makes an argument for procreative beneficence, his conviction that parents are morally obligated to breed the healthiest children possible. "Nature has no mind to equality, no mind to health, no mind to happiness in terms of the children that it produces," he explains."
In the movie Gattaca, parents were able to selectively choose their children through gene manipulation. Children that were born without this gene manipulation were known as "God Children". A two class society was created, if you were a God's Child, you were lower class.
I don't believe that modifying the human genome is going to bring the end of humanity. I know that mistakes will be made and damage will be done, but eventually we might get it right. Technology always advances this way.
What worries me, is genetic discrimination. DNA sequencing is getting faster, better, cheaper all the time. What use to cost millions dollars and take a long time, now costs a few thousand and can be completed in a few hours.