I personally would want a prequel to the Omaha Beach map, set a few hours previous. it would be the airborne invasion, which was I think between 2 and 4 hours before the beach landings. essentially, the entire American team can spawn at random points in the air and parachute down to take German AA and artillery positions before the beach landings. it would certainly be much easier than dealing with the hassle of getting all of those C-47's across the channel with everyone in them. maps can only be so big. 101st. airborne vs. German infantry. there could even be a few flaming C-47's and other things like that scattered around the map, especially to add to the effect of the night.
It has been pretty much agreed that it would be impossible to do a airbourne D-day map like the crete map, as the C47s would have to fly over the beaches, thus needing all the bunkers, plus the bunkers would therefore be part of the map, which is rather unrealistic, considering the para landed miles and miles inland.
Other than that, it would probably just involve the units being highly scattered, with actual spawn locations scattered wildly and widely throughout the map, against german infantry and AA. TBH, airbourne was not concerned that much with attacking and taking out artillery units on D-day night. Their job was mostly to link up with others, get to town objectives, and survive.