Yes you have to program the EPIC card yourself, but theres still the issue of getting the flight data (airspeed, attitude, elevation, etc.) out of the game and through the epic card to the device you're trying to use to diplay the flight data. Some programs have a digital version of this that streams flight data over a network to another computer and display it as a dashboard. This is only important for flight data output, or complex input that invovles more than a button push or a mappable axis. Input from a simpit can still be accomplished easily with a keyboard setup triggering button pushes. This is the ceapest and easiest way to date, and probably will remain the cheapest.
I think that this game sorely needs something like this, as most videocards now will let the user hook up another monitor if they choose. They have track IR support and very few of us have that! Not all of us have rudder pedals (though I need to get some). Having a way to export flight data through shared memory or other means could also open the possiblility of AH2 TV, letting others ride along from a suitable viewing gallery (anyone remember HLTV?) This would be a big plus for the game, and the devs would be wise to seriously consider implementing it. Not sure how the game is set up now, but it might not even be that hard.
But then again, im not a programer, I just play one on the internet!:D