A number of major U.S. retailers appear to be out of stock on certain models of the sixth-generation iPod nano, suggesting that Apple may be planning to refresh the device in the near future. 9to5Mac reports that Amazon is out of stock of roughly half its available nano configurations, Best Buy is similarly spotty in its availability, Walmart has only a few models in stock, and Target is likewise out of stock of several models. The report also indicates…
