The answer is definately. The sharper the knife, the less likely the cook is to cut himself. This may sound like dull-witted reasoning, but the point is valid for two pragmatic reasons. First, people tend to be more careful when using sharper knives because the potential harm is more vivid in their minds. Second, a duller knife is more apt to slip when cutting because it requires more downward pressure to do the job.
There are more benefits from a sharp knive than just safety. It makes cutting quicker, more efficient, and minimizes ripping and tearing of the food.