"New, creative solutions must be implemented if the commercial side of the hobby is to survive. A civilian flight sim is more likely to survive than a combat sim though, but a lot of us combat guys find this dreadfully boring"
I.e. stop trying to re-invent the world every time you want to move an object across its surface!
This is where a piece of software like Outerra could slot in nicely- Sim development therefore moves from trying to do everything well (scenery, physics, 3D graphics etc) to trying to do one thing very well (i.e. development of complex military aircraft systems and weapons or complex campaigns) while leaving a large part to an extensible 3rd party 'world'