My bets would be it is Fallout 3. But are you sure about the D&D license? If its Fallout 3 and they are not using SPECIAL then its a waste of time.
As to it being in development for over 2 years, that is true but not with a team. Until project Jefferson was cancelled it had one or 2 people thinking abotu a lot of stuff.
Rumour has it that Jefferson was canned because of the lost D&D license.
Myrthos
So it is written on russian fallout 3 fan sites and in rpg news. I have no idea where have they got info on engine and rules. I will probably spend some more time to clarify this. But, I have written that these unfortunately are more rumours than clear facts.