In a recently reported article a Sony representative had this to say about their console plans:
"We at PlayStation have never subscribed to the concept that a console should last only a half-decade. Both the original PlayStation and PlayStation 2 had life cycles of more than 10 years, and PlayStation 3 will as well. The 10-year life cycle is a commitment we've made with every PlayStation consumer to date, and it's part of our philosophy that we provide hardware that will stand the test of time providing that fun experience you get from day one for the next decade."
It makes a lot of sense, but the trend of longer life times is not something that is unique to Sony's devices. Release periods between new game systems have been growing longer since the days of the Atari VCS. Note the current generation of video game systems last for a lot longer than the ones that were out when I used to play them which were updated yearly.
Modern systems only have finite processing requirements given that so many have already maxed out high frame rate performance for 3D gaming (the most processor and memory intensive) at high resolution on the most used panels (today LCD and LED panels of either 720 or 1080 p resolution). All the necessary hardware muscle to drive that panel depth can safely be packed into a cell phone sized screen device today...in fact there are smart phones today that have the *same* max. resolution pixel (1920 x 1080) wise as the Playstation 3.
Once processing needs are maxxed out there is no real reason to deploy new hardware, you simply focus on making better game experiences with the hardware that is already *good enough* to give great performance on the games designed for it.
There is a reason why all the game console makers basically stopped even using resolution as a marketing strategy in their sell of the games when I was smaller resolution was a top of line item to tout that you had it above your competitors console because then you could *see* the difference, not any more.
The latest generation graphics boards and chips are now doing stuff that was unheard of 10 years ago *in real time* let alone simulating them using old tricks like various types of mapping or shadowing procedures. Real time physics is all the rage, real time object deformation, real time fire and water effects...the hardware simply has gotten far beyond the applications that the developers are programming it to perform.