The earliest estimated release date of the Playstation 4 is 2010, as said by Paul Holman (Sony’s VP of Technology). The stated reason for this is “Sony will introduce a series of firmware upgrades that will give the PS3 more media centre capability while allowing for the introduction of third party applications and hardware ’such as interactive controllers’ similar to the Nintendo Wii”

Even if Sony wanted to delay the ps4 as long as possible, not doubt Microsoft is working on a successor to the XBox 360, and Sony wont want be lose is postion as the premier console system when the next-gen console race heats up.