@Joe Nation,
I've been reading a lot about this (big article in the NYT recently that I posted somewhere) and what I've become convinced of is that the
barefootness per se is irrelevant. Running
style is the important part.
Thick-soled running shoes discourage the right style, and running barefoot encourages the right style. BUT you can run in the right way with shoes, too.
My preference at this point is running shoes with thinner soles -- not barefoot, nor "almost-barefoot" like Vibram Five Fingers, but not the huge padded things either.