>Hofstadter's facetious Law says that everything takes longer than you
>expect, even when you take Hofstadter's Law into account. On this basis
>I should further increase my estimate to maybe 12 or 15 years.
This brings to mind one of Clarke's laws, where he said something along the lines of 'everyone overestimates the short-term improvements in technology and under-estimates the long-term'. That seems to be generally true, in my experience.
I was being somewhat facetious with my original comment, but I still doubt we'll have workable fusion in 20 years from now. As I said to someone in private mail, I expect to be living off-the-grid in ten years, but I have no doubt that I will have to sacrifice some convenience and deliberately reduce energy consumption to make it work, and few people would accept that.