Richard Dawkins is optimistic about four things in his chapter of What Are You Optimistic About.
Prof Dawkins is optimistic that humans will find The Theory of Everything before aliens arrive.
The second thing he is optimistic about is that with The Theory of Everything we will then complete physics, but the enterperise of physics will continue.
With evolution by natural selection and The Theory of Everything we will create a sensible explanation for the existence of humans and the universe.
Prof Dawkins is confident that this will deal a deathblow to religion. I think this is unlikely, but if no people believed this, then they wouldn't have so much belief in science.