We could be getting a new super slim PlayStation 3 4000 series, according to a new FCC filing. The CECH-4001x model name is mentioned in a document filed by Sony, which also shows images of the internal radios of a suspiciously console shaped device.
This model name harks back to previous PlayStation models, with the current generation PS3 Slim being the 3000 series and the previous Slim the 2000. Extrapolating out, it would appear the new machine will be a slimmer version of the existing console. The site Euregamer supposes the new console will make an appearance at Gamescom in Germany next month.
Presumably this would be the final iteration of the console before a PlayStation 4 launches in the next year or so.