TexMurphy, there are things I cannot talk about and there are things I can.
I recall HiTech saying one time there was not much of the original game code left in Aces High. It is just the way HiTech does things. You cannot 'dogpile' code and have it run efficiently. From time to time you have to do a ground up rewrite and HiTech does. The constant updates insure those coded systems are kept up to date.
I am familiar with code and projects that get 'threaded' from too many fingers being in the pie. In our particular environment that is not an issue. We are much better off with the constant updates than most companies would be.
As far as what part of a model gets better looking. Well, the big adder in the next release is bump mapping, which adds a lot more detail to the models. If they only bump mapped the yoke, the same amount of resources would still be used, so it makes no sense not to do the entire model.
I cannot address the environmental stuff as that would require speculation on the future, which I am not privy to.