I have to admit, of the four, Karpathy and Sutskever were the two I was most impressed with. I hope he goes on to do something great.
When the next wave of new deep learning innovations sweeps the world, Microsoft eats whats left of them. They make lots of money, but don't have future unless they replace what they lost.
E.g. Oppenheimer’s team created the bomb, then following experts finetuned the subsequent weapon systems and payload designs. Etc.
Engineering Level:
Solve CO2 Levels
End sickness/death
Enhance cognition by integrating with willing minds.
Safe and efficient interplanetary travel.
Harness vastly higher levels of energy (solar, nuclear) for global benefit.
Science: Uncover deeper insights into the laws of nature.
Explore fundamental mysteries like the simulation hypothesis, Riemann hypothesis, multiverse theory, and the existence of white holes.
Effective SETI
Misc: End of violent conflicts
Fair yet liberal resource allocation (if still needed), "from scarcity to abundance"