[EGOvoruhk]

That's a terrible analogy. I can't go get a plain burger from McFattie's and run a CAB file to "install" thousand island dressing and turn it into a Big Mac

But if I had a plain ROM, I could run a few CAB files, and have it look just like many of the custom ROMs out there

Personally I think it's a good idea. Have a few base ROMs that consisted of things that aren't CAB installable (Like 6.5), and then just start releasing add-on packs. It would pretty be like a computer. You install Windows, and then whatever else you want