It is down the same alley as FSX modules with legacy aircraft, with the addition of modeled weapon deployment. If ED was to make a wrap around the Mustang with a WW2 era environment, opponents, and ground targets, all with the same fidelity and attention to detail as we are used to, then it would take forever.
If you cannot enjoy the P-51D in DCS for what it is, which is a realistic flying experience of the plane itself, then you really have nothing here to do, and you should go play BF3 or something. (I do when I feel like it.)
Lost