The R&D budget may be tiny for a company this size, but it has apparently been tightly focused since Steve Jobs returned.
With this much money in the bank, I kinda wish Apple would re-establish a skunkworks R&D dept. to think different and do basic research in related areas.
Personally, I'd like to see some major efforts in the physics of light and lenses. Is there a radical new technology that would allow them to create tiny zoom lenses, for instance?