It's just typical 'patent everything you think of whilst on the toilet incase it actually was brilliant' behaviour.
It wont work for exactly the reason the Wii HD would never have worked if it existed .
Game designers have the choice of;
Make no changes to code = no improvement
Make the game use more ram = severely reduces customer base
Make the game use more ram bundle the addon with your game = expensive
Program 2 games that have the same plot, gameplay etc but different graphics and put them on the same disc/on 2 seperate discs = expensive
Run the same game code but with minor tweeks, extra ram means you can increase draw distance if the person has the addon = a slight improvement but not really enough to justify the investment, either for Sony or for the customer.
We shall see the PS4 quite soon, and this 3.5 shit is a fantasy
