PyCon: Eben Upton on the Raspberry Pi

Agreed. For kids, I suppose this can really be their very own inexpensive toy, while an actual PC (even if its "their PC") is more of an expensive tool that we, parents, provide them.
BTW, the hopefully reduced barrier for entry for low income family may be beneficial too...

There is also the issue of simplicity: the Pi is a computer, but it is a simpler one than a modern PCs which is nearer from a supercomputer than it ever was.
Imagine getting a Cray Y in your home 30 years ago instead of the Apple II. Would you have dared open it? What about these now forgotten parallel Fortran extensions? Argh... Back to playing on the console.

I agree that Minecraft idea is brilliant. Btw, Minecraft success itself may be based on the same ground: simplicity, reachability.

As to boys vs. girls, I have no clue yet personnally; but I agree that this is an important question. The most astonishing is that girls seem so uninterested that they do not even bother taking the time to explain why programming apparently is so uninteresting to them...