I helped test the microbit and I wrote a small program for pedagogical purposes. The hardware was very neat and I liked the leds on the back.

Originally there was going to be a coin cell battery but they removed it because children might eat it. Also there is a Bluetooth radio on the microbit but the runtime was 12k and there wasn't enough space to load micropython and Bluetooth at the same time .

A link to the example is here https://github.com/bbcmicrobit/micropython/blob/master/examp... .