Although PS4 is set to launch this holiday, Sony isn't letting PS3 go to rest. In fact, it appears that the company has plans to update the PS3 with yet another SKU. A set of certifications filed in South Korea and Japan indicates the company has something up its sleeve. However, don't expect a total redesign a la the Slim and Super Slim. Instead, it's likely the new-model PS3s will rework some of the current system's internals.
The first number following the CECH prefix typically indicates the generation of the hardware. Sony's PS3 Slim launched as CECH-2000, and 2100 and 2500 SKUs followed with larger hard drives and reworked internals. It's likely that the jump from the current CECH-4000 to 4200 series will result in a similar, nearly-invisible leap for consumers.