Arduino is really something special. As a kid I'd always been fascinated by electronics but didn't really know what to do with that energy. And then I grew up and just assumed that, well, that's over.
And then Arduino comes along and, with its simple little IDE, convinces me that this isn't so different from the rest of my programming.
And now I get to build stuff. With my hands. Makes me feel like a kid again.
It's amazing how much you can accomplish, as Banzi has, when you can reduce something to solving a user experience problem.