Somebody woke up on the wrong side of the nest this morning.
Those aren't really the parts I'm using for the concept document of the actual version of Plix!, a couple parts in there exist solely for the purpose of making it "sellable to publishers." Think "role-playing" that I'm some third-party development team trying to sell the idea to a large publisher; Expanding things to other platforms and names like "XBOX Live" make publishers cream themselves and make it a little easier to sell a game idea.
On top of that, for the real thing, I am planning on using an arbitrary library, and the only thing that will be necessary for porting will be changes in what the graphics engine uses. The Windows version is going to be using Managed DirectX, the XBOX 360 version will be XNA (the only real problem I have with that is having to send all of my audio through XACT for the XBOX version), while I can use Mono & OpenGL for the Linux and Mac versions, all while changing nothing about the Game Engine's code.