(Apple mouses only have one button too)
Ah...good point: the button. But there are so many more possibilities.
I like the idea because of its simplicity and robustness. Can it be programmed with Arduino IDE?
3) The tools used to program will be completely open source. Most likely the Atmel Atmega/Attiny tools such as WinAVR for windows and AVR-GCC for linux/mac.
Windows came from Xerox Parc