I can't help but think how many variants we will see of this airframe, surely not as many as the K/C/E-135, but I wonder if the miles of wiring and open archetecture will weigh in its favor to help secure future projects like replacements for AWACS, Mercury, E-4, J-STARS, VIP, W, l@ser redux, etc.
Automation and reduction in the size of electronics make it highly unlikely any airframe of this size and associated crew will be required.
The E-8 replacement is now intended to be a business jet; the USN is replacing it's NP-3D range surveillance aircraft with
G550 CAEW etc. Everything points to the E3 force being replaced with similar sized aircraft in an integrated net with off-board data fusion.
So, except for the KC-Y, KC-Z competitions, I can't see it. Pax aircraft such as the C40 are more likely to be replaced with off the shelf 737 or 787 models.