I'm guessing it would be something like this:

The core members (always in): BYU, Boise, Houston, UCF, Cincinnati
The common members (usually in): SDSU, Fresno, Memphis, USF, Navy, Air Force
The contributors (sometimes in): Colorado State, Temple, Toledo, ECU, App State, SMU, Tulsa, Utah State, Southern Miss
The randoms (occassionally in): A hodge-podge of schools that have a successful season here and there

What I would be most curious about is seeing how big some of these programs could get without limitations on them. Without being tied down by the G5 label, and having significant reinvestment into their programs I would expect some schools to really explode and become big time programs.