The only chance an American F-16XL or any F-16 derivative will fly is if the JSF gets cancelled. Lockheed is unlikely to do anything that will remotely eat into the F-35’s market.
Somewhere down the road a few years, all those aging F-16s...who knows? I see market potential and that's a sexy upgrade to the standard retrofit package that market will be offering.
Just a day dream. But then, I still live to see the F-23 fully developed and in service. *sigh* What a great F-14 replacement it would make, not to mention revive the "who has the better fighter argument?" between the Navy and AF.