almost certainly 10+ years. I read The Age of Spiritual Machines (which still sits on my bookshelf) probably 20 years ago. I work in tech and have seen and participated in the arc toward the singularity. I'm more optimistic in the sense that the trends that were identified 20+ years ago are still chugging along. As others have mentioned there are persistent (and perhaps intensifying) threats to the continuing progress of humanity that may disrupt our progress toward the singularity itself, but if we can manage to keep from completing borking the modern world we have built, I still feel like the next decade or two are going to bring some pretty foundational changes to our world.