will the nwn2 engine support as many units as the dragon age engine?

That's a cool shot and definitely instancing at work. But, I will say this. What you see in that shot is actually pretty straight forward. In fact it's easy when you have only a single directional light in the scene affecting ALL instances in the same manner. On top of that, those instances all share the same everything literally (geometry, textures, etc). We'll have more dynamic lights in our scene, as well as a lot more customization available on a per object basis...and it's for those reasons, that instancing for us is quite a challenge.