I co started this project with Thor when I was in middle school.
I'm now in college and only one third of the "demo" chapter has been released. We originally planned the demo as a way to get something out a bit quicker, because we could start work without worrying about get new Vasudan models. However let me say that the quality of the first chapter has far exceeded anything I could have imagined during the first stages of the project.
I've been keeping track of progress out of curiosity over the years and considering the main workers are devoting time to other projects it's amazing what has been released has been released. With ST:Reborn done, some of the developers may be freed up, but I can't speak for them.
If I recall from the demo when I played it, there are a number of ships and weapons available. If I have the authority, I'd like to encourage fans of the project to FRED stand-alone missions or mini campaigns using the files available. While I wouldn't advise stepping on the official toes by fleshing out the rest of the Unification War, I'd be interested to see small conflicts between some of the outer factions. Maybe give us reason to distrust the Kuiper Federation or tell the story of a security guard defending gas miners. If Freespace 2 is a World War II style dogfighter, this is World War I.
That's if you don't want to try and help them finish the official missions.