While I think it'd be difficult to fully learn how to implement something from this (read: tedious), I do see it as a cool way to learn how other people think about and solve problems. If it means anything, I watched a good five minutes of the guy working on the Arduino code without thinking about turning it off.
I watched notch develop Prelude of the Chambered over a livestream a couple of years ago. It took a couple of days, but I picked up so much (I went on to port it to Ruby, bizarrely).
While I think it'd be difficult to fully learn how to implement something from this (read: tedious), I do see it as a cool way to learn how other people think about and solve problems. If it means anything, I watched a good five minutes of the guy working on the Arduino code without thinking about turning it off.