Exactly, something similar to that.... Granted with some things there will be a carrier difference (like VZW and Sprint carrier differences, but those could be resolved by a cab for the extended ROM, or an OEM.. Like how the carriers do...)
The better we make the base kitchen, the better all the custom ROMS that come from it will be.
It would also allow the less savvy users to download the latest base kitchen with all the fixes and simply add their own OEMS into the mix and build. :P