Master, eh? Well, according to Jason. Hmmm…. I think it's pretty meaningless really, since I don't think traditional craftsmanship is a particularly good analogy for software development. It's useful in that it tells us to consider apprenticeship as an appropriate way of learning, but I think software development on anything other than a very small scale is largely a social activity, unlike traditional crafts.
Also see the discussion on John Wood's page.