Bob
I think with any flying you have to have a mission profile and choose the aircraft to fit your mission profile.
If your profile is a flight around the local area on a sunny Sunday afternoon you don't buy a CJ2
If your Mission profile is to fly deep into Europe for a distance of 1200 NM with six business associates and you or your company can afford it you buy the CJ2 or whatever fits your budget.
In between there are singles some piston some turbine and there used to be a lot of piston twins and turbine twins for those who didn't trust a single at night or in bad weather.
We also now have the VLJs like the baby eclipse which was probably targeted at the twin market with tiny jet engines that sipped fuel.
Interesting is the Cirrus a single engined jet but with the Cirrus notorious BRS which has proved itself time and time again and in many ways gets over the single engine fear.
i could see more development in BRS systems and single engine in either baby jets or baby turbo props for pilots who need to travel at low cost.
The biggest problem will still be a shortage of destination airports with approach aids which are low cost to access.
Pace