Possibly a top-notch first-party keyboard from Apple that turns the iPod into more of a laptop form factor when you want to use it as such. The kind of thing Microsoft is doing with the Surface. As much as Windows RT is pretty useless, the Surface keyboard is a really nice piece of kit.
There are already very good third-party solutions (though the better ones tend to be expensive); not sure why Apple making one would make a huge practical difference.
