Were the Solo introduced 10 years ago, the 9 mm release would have been followed by a .40 S&W release.
The responses to this thread is an excellent indication of how the hype has fallen off of the .40
While not a bad round in a mid to full size gun, it IS much more difficult to control in pocket guns.
Demand will dictate if Kimber invests in a .40 Solo
Personally, I like the .40 in my SIG 226 but would not touch a mouse gun in this caliber.