I'm not great with the mission editor myself, but what I'd really like to see in a MP server is a multi-mission semi-dynamic "campaign". Especially with the WWII map, a D-day campaign would be awesome. I guess the mission maker would make one mission, and the server could run it, and the mission maker could take the info on who won, how much they killed, and make another mission, (maybe from pre made template?) using those numbers, and the location of the ground troops. The server could then run these campaign missions once a week, to give time for the mission maker to edit the next mission.
These missions would have objectives, but maybe to put an emphasis on air fighting, you wouldn't need all of them to win, or maybe AI bombers (once available - Sithspawn you were working on a B-17 right?) would attack ground targets, and the fighters could do escort/intercept, while P-47s and other attackers (Is VEAO making a Typhoon?) could also go for the ground targets.
TL; DR, a WWII semi-dynamic MP campaign, running once a week, with objectives, but an emphasis on a2a.