According to a new FCC filing, a new PlayStation 3 model is in the works. Sony is working on a 4000 series PS3. It might be a newer slimmer PS3, which was rumored to be in production by Eurogamer, and is going to be announced next month.
The current PS3 model is 3000 series. The model mentioned in the filing is the CECH 4001x.
A image is included which shows the new model which looks a lot more slimmer than the current one.