Looking at the characters on the title screen it looks a bit like the origional half life engine or the unreal engine that was used on Postal 2. Can't quite decide!
Hopefully it will be worth the wait, should be decent enough I think personally with it being completely different from most other games. Closest thing that comes to mind is Riddick EFBB. Once it is online we should create a HEXUS Mob, should be pretty cool getting into gang fights and riots!