http://9to5mac.com/2012/09/11/new-ipod-codenames-touch-is-n78-nano-is-n31-shuffle-is-n12b-iphoneipod-touch-panorama-mode/

Alongside the information we have already posted about the new iPod touch, iPod nano, and iPod shuffle, we received possible code names for the devices. Like @chronic, we’re hearing that the new iPod touch has the internal codename of N78.