The next major release of Wing Commander Invasion is not due out for quite a while, but Major Payne is already hard at work. He's recreated our own Solar System for use in the Empire at War mod and planning to add the Nephilim as a faction. We can't wait! Try out the current release here.
I've gotten ALL the planets for the Sol System (although Saturn is missing its rings but don't worry. I will have a reason for this), as well as more custom projectiles and sounds. The concussion torpedos that the likes of the Wasp, Ekapshi MKII, certain capital ships and starbases use have been changed for actual torpedo based weapons. I also have setup 3 custom missiles for fighters but these won't be implemented just yet. Once I've retested and checked the current v1.2 alpha I'll go on to create a special Galactica Conquest based around only the Sol System. It'll be more of a "what if" scenario as in what if the Kilrathi were on the Confederation door step.
I think I will most likely be adding in the Nephilim as the 3rd side as I have an idea for another GC based around their invasion so that'll be added in a later build. The next version planned for released is a v2.0 so its a bit of a way off yet.