Regarding all the E-8 J-STARS replacement discussions:
USN is trying to leverage its way into the radar ground surveillance business. All the P-8s will be capable of accepting the AAS radar, which does everything the J-STARS radar does and lots more. The airframe already has lots of processor power and display/control consoles, cooling, on and off board networking, etc on board, so all that would be needed besides the radar hardware is additional software in the control consoles. So putting a J-STARS capability on a P-8 will be MUCH cheaper then developing a dedicated replacement for the E-8. And USN will have hundreds of P-8s vs USAF's 16 E-8s, which should provide operational cost advantages.