I think the tax idea is interesting. They have it 55 years after the singularity. I've heard (singularity advocates) say that once the singularity occurs our economy will double every few months. That means that after 55 years the average person would earn 9 figure salaries. At that point the government could probably pretty easily run on donations versus taxes. If thats the case I think 55 years after the singularity is a conservative estimate. I'd bet it will happen less than 5 years after the singularity. Assuming the singularity occurs of course.