They should make the DS4 50% larger than the DS3.
And replace the 4 shoulder buttons with 2 mega shoulder triggers (that could be clicked forwards, backwards, or center).
Then add a multi-touch pad on the back that can simulate in game surface textures by further advancing on the tactile pixel technology Sony patented a few years back.
http://www.engadget.com/2008/06/30/sony-applies-for-tactile-pixel-haptic-touchscreen-patent/








