MP3 was meant as an example of how the Arduino code would be shared/applied. In other words, like MP3 where you have accomplished music talents creating the songs, in this case we'd have accomplished Arduino code writers creating the applications. End users just download MP3 files right into their MP3 players, smartphones, laptops, iPods, or whatever plays the MP3 songs. Drag and drop or something similar - No fuss, no muss.
Likewise I'm imagining an scenario where end-user don't have to think about "Arduino binaries" or "Arduino IDEs" or even a "sketch". You simply read about some Arduino signaling application that makes a detector/relay module fire on every 20th trigger, download it to your PC/laptop/smartphone, plug in the $2 Arduino via the included mini-USB to load the application, then you're done.
Sure, learning to write your own sketches and learning about IDE's can be a rewarding and interesting life experience but it's not for everyone.
