In fairness to those criticizing Kurzweil, the timing of his predictions _does_ matter, because he's arguing that technological growth is a fast exponential, leading to super-human intelligence by 2040 or so. So if he's off by 5 years on wearable computers, he might be off by 40 years in his ultimate prediction, or growth might be an s-curve instead of an exponential.
No, I really think that Kurzweil's claims of a technological singularity within our lifetime are extraordinary enough that he should be held to very strict standards of timing and prediction. Good grief, the man eats strange nutritional supplements by the handful in hope of living an extra 10 or 15 years and thus, by his theories, living forever.
