Few months back I posted a screenshot from an internal Best Buy message that listed a Nikon product under the code name Q750. The Qxxx notation is an internal Nikon numbering scheme - basically every Nikon DSLR camera has a code name that is different than the actual product name. It was suggested that the Q750 could be the code name for the Nikon D7000.
Recently a new code showed up in Best Buy's system - Q740:
Q740 stands for Nikon D3100 according to this Nikon press release:
Best Buy have clearly adopted Nikon's internal numbering scheme in order to prevent leaks since they have to setup their inventory ahead of a new product announcement. If you are working in a retail chain, keep an eye for any future Nikon Qxxx notations.