SONY has there research/patent teams were there sole goal is to innoviate and with it patent everything new. many companies have the same teams.
SONY been working on the PS4 since before the PS1, hence when they started working on game products. Because you you are creating an product and you are apart of an company like sony you are told to keep pushing the bonderies and so to say they are working on the PS4, its that they have been working on it for an while. There would be teams dedicated to it from the networking department thats been working non it for around 5-10 years now, and the electronic reserach teams would all be trying to find new tech for there game systems as well.
Of Course That's Just My Opinion, I Could Be Wrong