I agree with Topcat and Beaz. I think the markings should represent units or individuals aircraft as a tribute to their deeds.
It is also nice to see Pyro et al actually respond and listen to our requests!
I also would like to eventually see the ability to edit the a/c 'skins' ala what Microprose just released for EAW. This would be something that works on your FE only, I don't want to see anything added to the what needs to be transmitted as part of the data, like what HT said. However, for scenarios especially, if we are to be allowed to create our own terrain, it would be cool if we could offer correct markings that would be a separate optional d/l to correspond to that terrain. IOW if someone did a Finnish campaign terrain, with lots of snow, it would be cool if there was an optional art set that had the I-16, MiG-3, LaGG-3, Me-109, Brewster Buffalo, Fokkers in correct Finnish and Soviet markings and in winter camoflage.