In the past, console hardware companies do a technological refresh and release new game consoles every five or so years. However, the massive worldwide recession that happened in 2008 was a big reason why we haven't seen any new consoles from Nintendo, Sony or Microsoft by now (Microsoft launched the Xbox 360 console in 2005 while Sony and Nintendo launched the Playstation 3 and Wii consoles, respectively, in 2006). Nintendo does plan to release a new game console in 2012 and will reveal more details about the product at E3 in less than two weeks.
Now, Sony is hinting that it has started work on the successor to the Playstation 3. Venture Beat reports that during a conference call to discuss Sony's latest financial results, For the home equipment the PS3 still has a product life, but this is a platform business, so for the future platform – when we’ll be introducing what product I cannot discuss that – but our development work is already under way, so the costs are incurred there.”
That is the most a Sony exec has stated in public about the next version of the Playstation. However, that doesn't mean that the company is dumping support for the PS3 anytime soon. Indeed it's likely that the PS3 will have as long of a shelf life, if not longer, than Sony's Playstation 2 console which is still being made and supported over 10 years after its launch in Japan in March 2000.