A terrific PopTech speech by Eben Upton, who started the Rasberry Pi foundation, on the lessons learned in creating what turned out to be a fantastically successful $35 computer.
“I remember sitting down with my wife for dinner...and we had this sudden, appalling realization that we had promised 600,000 people that we would build them a $25 dollar computer.”
What's clear is that he intended it to be like the BBC micro, a computer designed to be programmed. As such it's optimized for multimedia and outputting to a monitor. Unlike Arduino, which is optimized for I/O and interfacing with physical stuff (lots of analog and digital/PWM inputs and outputs), Raspberry Pi seems to be more oriented towards graphics.
Some good lessons on resilience, too. Some things didn't work, others took longer than expected and with great promise comes great expectations and no small number of critics. They just kept improving, adapting, learning and powering through. Inspiring.