Well, okay. The old sound packs won't work anymore, so everything has to be built again. The sounds for guns can work, the alerts, things like that. The engines for the airplanes and vehicles will need a little more care. I have upgraded my M3 to work in the game, but the surfaces of the terrain actually modifies the sound of the halftrack tread, so I know there will be other surprises.
Bustr pointed out that the lower end of rpm could use more interest, which is something I was planning on. I think you will like the bombers for the same reason. I think the FMOD engine will even allow a little random change there, but I haven't played with it to see if it really is possible. I'm talking about the coughing, sputtering as the engine starts up, or if you leave it in low throttle, etc.
My biggest interest is in the external sounds. I don't know how far the airplanes can even be heard, but I am anxious to push the boundaries.