Looks like The Viper is a high priority on DCS Aircraft Development list.......
from Wags.........
"While the F-4E is still planned, we have other modules in higher priority like the Hornet, Yak-52, Mi-24, F-16, and AH-1. Focus on the F-4E will come once we clear several of these projects.
So, I would not expect any F-4E news for quite some time."