I do wonder if kids will really show any interest in this.
I am of the BBC Micro/Sinclair Spectrum generation and my ZX Spectrums got me started programming. But 90% of the time I was playing games on them. If the only thing they could do was allow me to program myself then I dare say it'd have been consigned to the back of a cupboard.
This device looks quite cool and I like the idea of an online development chain to get going easily & quickly. I just fear that kids will soon get bored of making LEDs blink in different patterns.