It's not set aside. DFW is next in line after KLAS. The only thing is they're still uncertain whether or not to make DFW for both FS9 and FSX, or FSX-only. Either way, after KLAS, they're making it. That's what they said, anyway.
Anyway, after they make DFW, they've said they're stopping work on airports for the time-being and will make an FSX-only fighter plane.