Shuhei Yoshida, Sony Computer Entertainment Worldwide Studios Head, has told Develop in a recent interview that Sony is working on new hardware. Of course, it's not really odd for Sony, or any manufacturer for that matter, to be working on a new system, but an open announcement like this does seem like a hint at something coming in the relatively near future.
The most logical hardware that has been rumoured for quite some time is the PSP2 that was initially thought to see a release during this year's E3 press conference. Yoshida stated that Kaz Hirai, President of Sony Computer Entertainment, wanted to get developers involved on the new project.
Oddly enough Nintendo said they also had a lot of developer input on the new 3DS system which was announced at E3 this year. All signs point to a hopeful PSP2 in the works for a reveal as early as Gamescom next month. If this is is about a new home console, this may mean we would see a PlayStation 4 in the not too distant future. As for now, everything is just speculation.