That's an interesting idea, now let me tell you why you'll never see it. First of all, I assume the controller ports and internal fan are attached to the case and Nintendo would probably be afraid people would break something. Second, and this is a big one, I guarantee you Nintendo Doesn't want the average Joe poking around inside the system. Can you say "LAWSUIT" the first time some idiot tries to put on his shiny new case without unplugging the system and gets zapped. Remember this is the country where you can sue McDonalds for burning yourself with hot coffee. Unfortunately, idiots and lawyers do exist, which keeps the folks with enough common sense to unplug the system before switching cases from ever having the chance to.
TOY