Nissan does have a new Silvia/240sx in the works, it was supposed to come out around the same time as the FT86/BRZ but the project was put on hold due to the economic crisis in 2008-09. It was around 70% complete at the time including the exterior. It will probably be a few more years but Nissan has supposedly started back on the project, here's a link to a Motortrend article with more detail and here are some pics below.
http://www.motortrend.com/future/fut...a_second_wind/
Nissan S16 Silvia/240sx Concept:
Nissan ESFLOW Concept:
