I've finally managed to get my hands on The Lieberman "letter": Foot strike patterns and collision forces in habitually barefoot versus shod runners reported in January's edition of Nature and I've read through it, the accompanying Harvard site and a lot of the reviews other people have made, and here are my observations.
First and foremost, I believe this paper has been over-hyped and misinterpreted (possibly deliberately as it makes "good news") in a big way. I think the main reason for this is it's the first major research paper in years that actually involves comparisons between barefoot and shod runners. There have been other recent studies that have documented the merits of different foot strikes (fore/mid/heel), but none have made the comparison between barefoot and shod runners. There's also the added attention barefoot running is currently enjoying thanks to Christopher McDougall's book: Born to Run (my review).
