I'd say from all the responses on this forum, force feedback will be there...someday...

Pacific theatre (before Med or other areas)

realistic external merlin and other external aircraft audios.

will be sweet for movie making , having nice external audios,

failing this make the audio edit friendly open format.

All I want is a co-op dynamic career mode and more theatres.

Obvious and easy selecatable skin settings for aircrafts (like in IL2).

more theaters
and a MUCH better campaign system with cutscenes,deatailed briefings ,REALISTIC debriefings (not just a story that totally ignores what happens in the mission) and if possible dynamic.At least don't show the "next" button in if you totally fail or put or put it as an option like the old IL-2.
More SP missions,more maps.
Better weather and clouds

1++++++

Instruments easily displayed on a second monitor and other considerations for cockpit builders.

Some sort of FF for seat, but not in the joystick for my preferences at least.

bringing life to the airfields, with the list of all available pilots and wings

Air Raid Sirens on the fields, a dynamic campaign that lets you take part in the last moments of the BoF up to the final days of the BoB, including the evacuation, awards and ranks for your campaign, more variants of the Hurricane and last but not least drop-in missions to randomize what you are up against.