the nano is just amazing. apple will sell a zillion and their stock price will go up because of it.
the form factor puts it in another class of products. it fits horizontally on my wrist and its screen is suprizingly high definition. use the same form factor, have the whole face be screen and add touchscreen, with a completely open source operating system and development environment. then i'd have something like the wrist computer from the Predator movies. oh and add blutetooth or wifi if possible. i'd almost never take it off.