There's nothing else to a tablet if you're one of the scores of computer makers that has already done exactly that (tearing off the lid, keyboard, and touchpad and put in a touchscreen).

For Apple, I don't know. They haven't invented it yet and I've learned that they can be more creative with years of product development time than I can be with a few minutes of writing comments. But they sure as hell won't release something that isn't significantly different in some way than what's been released before in the tablet space.