Gosh where to start.
I think the sentiment of this thread is great, though a healthy dose of realism means that we need to wait for the current proposed development to conclude. This means the map (which may be far larger than just Normandy) plus all those components to make the environment live - A6s to A8s, D9s, G6s to K4s, Spits, Typhoons, Tempests, P47s, P38s, ground objects etc etc etc. Bombers would also be cool but personally speaking it's much more fun to do jabo stuff.
But this is dreaming a bit - maybe we'll have all this by 2020. Following on from that, my wish list would be:
1. Desert (but you also need early Spits, Hurricanes, Lots off P40 variants, A20s, F2, F4 and G2, A4s, Ju88s, Bf110s, Ju87s etc).
2. Malta/Sicily (see above but remove the P40s and add Beaufighters, Blenheims, CR42s, G50s, Macchis and all the funky Italian things).
3. New Guinea would be excellent because you have a mix of all types of missions, but although you can forget the LW aircraft you'd need all of the allied planes plus the Japanese aircraft.
I really really hope that more developers jump on the bandwagon to develop for DCS. Fingers crossed.
Hood