Many of the "ideas" I've seen in this thread already exist - and many more are already possible.
Orbiter has one of the most complete (and well documented) API's I've ever seen. The possibilities that already exist have only begun to be used.
I, like many of us, have a dream of the "ultimate" game - and my vision of this differs from the vision of many - if not most - other orbinauts. It incorporates elements of RPGs, transport/trader sims, 4X games, and vehicle sims.
My "vision" goes something like this:
You are a young person who has just reached adulthood, and have joined the "teamster's guild". You attend "school" - a short tutorial on operating forklifts and cranes, etc. You take your "cargo handlers" test - where you load a few craft, drive a few forklift "missions", truck driver missions, etc. Once you get your "license" you get a job and set a schedule where you allot time for work, socializing, etc -sort of like "The Sims". You can then sort of "fast forward" and make money and friends. Once you get some cash, you could buy a truck and go to the "guild office" and take a contract to, say, pick up a load of widgets at factory X and deliver them to warehouse Y. You would actually drive the mission once to establish a "route" which can then be "auto'd" so you can fast forward again. Once you get some more cash, you can buy another truck and hire a friend to drive it for you. You would also rent an office - and take on another contract. Fast forward again until you have the cash to expand, etc. As you gain cash you can go back to school to get a pilot's license, rent a warehouse of your own, and essentially set up a ground based transport company, expand into a air transport, and eventually into space transport. Each time you would have to actually fly/drive the mission to establish the "route", and then you could hire another person to perform that route. Eventually you rent space at an airport, then a spaceport, etc. Once you a space vehicle, you can explore other planets/moons, create mines/factories/bases there, etc.
You would be able to walk around the bases, visit bars (to get "rumors", meet people, possibly fulfill a story line, etc.) All of your assets, employees, vessels, etc would be managed by your computer "tablet", etc. Essentially allowing you to build a factory/transport/trade network (and solve whatever mystery is presented by the story line).
I think you get he idea.
Pretty much all of this is already possible - but difficult. The First Person (RPG) part, "Sims" part, ground and air transport stuff would be handled by a game engine other than Orbiter. OrbiterNG would actually only be used to perform the math to simulate the spacegoing vessels and stations, etc.
But that's MY dream - and not everyone shares that dream.
Orbiter's biggest strength is in the modularization of it's elements. Having the sound and graphics done by modules (rather than in the core) makes this possible.
I like the open source model - but I've also seen many great apps get "forked" to death. I like that Martin is focused on the physics core - it allows for great flexibility without confining us to only one person's "dream". I don't care about space combat - but others do - and I would like to see us all get what we want without being forced to deal with things we don't want.
Sound and graphics don't need to be handled by the core - and shouldn't be (except for basic graphics for those who want a pure simulator). Collision detection (both vessel - vessel and vessel - terrain) and perhaps weather are probably best handled by the core - but most everything else should be handled by modules - so people can have the experience they want - not the one that someone else thinks is best. From what I've read, Martin is already working on these features.
I'm perfectly content to have Martin working on core features only. He has handed us the tools (API and documentation) to do the rest ourselves - and on a golden platter. We have only ourselves to blame for not taking advantage of the gifts he has given us.
After all, not everyone wants the RPG, Transport Sim, economic simulation, etc.
For those of us who do - we should get off our lazy butts and develop them ourselves rather than expect Martin to do it for us. Isn't he doing enough already? And for free?
You are a young