MY COMMENTARY:
I believe the "milkman" is actually a metaphor for the modern notion of increased shopping, purchasing, and delivery of goods without going to stores. If we consider the 'return of the milkman' as exactly that; the person who delivers commodity goods right to your doorstep -- then I believe we're on the cusp of that person being a huge part of daily life again.
If stores continue to provide a lousy experience (as many do today), why should we shop them if we don't have to? If a delivery option is available, as it increasingly is, why would I want to spend precious time experiencing poor service, overstocked shelves, bad music and no parking all wrapped up in an antiseptic shell?
I say, bring on the milkman! He's already providing a much better experience than what I'm feeling on a daily basis at retail. The more milkmen, the more the retail experience will improve--or go away.