I've always been a fan of Cyberpunk and the way it sees the future of modern technology. The exploration of ideas of cybernetic augmentation and how it can potentially change the way we interact with the world is actually pretty important. The technology is pretty far off, but the great writers of the 19th century were also dreaming of things like spaceflight centuries before it became possible.
As for the game itself I except an unrivaled level of immersion into the word and an incredibly high level of customization. As someone who spent almost 150 hours in Witcher 3 exploring every inch of that world, I expect CD Projekt to deliver an experience of even higher quality. I also am really interested in the plot and the potential this world has for corporate and government intrigue as well as complex personalized storytelling.