To be honest, I only hope for better models and animations for infantry, and to include a paratrooper model (where you have infantry troops under a parachute canopy) for the mission editor. The biggest thing that they need to do is to make the non-playable aircraft do a lot more in the simulation.
Why have a C-17 and helicopters with no ability to transport troops and equipment? It would just make the sim more realistic and will greatly enhance missions. I shake my head at times when I make missions because I feel very limited given the lack of use of AI aircraft that could make my missions more dynamic.
I know the devs may be busy with other stuff, but I honestly feel that dedicating to making the AI aircraft have more ability with respect to actually transporting troops by parachute, landing them at DZ's, or dropping equipment, would be a great addition to the sim.