One of the stated reasons for going to 6.8 mm is the preponderance of body armor in modern armies, and the need for a larger round to penetrate.
I'm not sure how this will impact the civilian market, unless folks are looking to hold off well equipped gangs or SWAT teams. Or they are like me, and prefer to shoot a larger round.
I'm not sure I buy the "modern ammo" argument for the transition from .40 S&W to 9mm. All pistol rounds underperform when compared to rifle rounds. Lower impact pistol rounds underperform more. I think the decision to go to 9mm was because of a combination of cost (both the ammo and replacement handguns - .40s wearing out at a much faster rate), and the increased number of lower strength recruits that are not able to shoot the higher impact round well enough to qualify.