An interesting blog by PC-12 shows early thinking on a future development.  We may still see the return of CFS, in a more FS compatible manner (as CFS2/FS2002 was).

It is still VERY early to even say what it will encompass, but my personal feelings are that it should be more of a "toybox" , containing a good set of basic building blocks, and then let third party content providers flesh it out with models, missions, campaigns, etc.  In my opinion, that's what made CFS2 such a success, along with  a certain interchangeability of models and scenery between FS and CFS - which is where CFS3 fell short (*note - this is my opinion, and in no way disparages the fine models made for CFS3)

*My* choice for "building blocks " era for CFS-X would be the interwar (1919-1939) period, if only because there was more experimentation, a variety of aircraft, and aerial conflicts that spanned the technologies between WW1 and WW2.

FOr example, the Spanish Civil War saw the Bristol Fighter in combat, - the last vestiges of WW1 technology - as well as the earliest of the "modern" WW2 fighters - Me109, etc., as well as other interesting and converted types (DC-2 bombers anyone?).

On the other hand, a WW2 "rehash" has the "simplicity" of allowing for the changing technologies - props to jets and semi-guided missles ....

I thought FS-X is interesting, but I can see better things beyond!