The XO is targeted at the poorer sections of the world. It is marketed as rugged, dust resistant, water resistant, but what happens when the prefabricated parts break down and their are no parts suppliers to go to? Children need to be able to learn what parts of their computer do what, too, not just how programs run on them!
XO hardware should be easily accessible and be replaceable by improvised parts - Keyboard gone? Maybe it can be repaired with readily available materials - maybe the repairs can be documented for the child to follow and learn?
The XO has its aim on teaching children about computing technology who would otherwise be unable to even get near a computer. The XO should let them get even nearer than just the programming.
Why package a generator add-on when the child would be better served to learn how to improvise/build their own?
The focus of this project would be to create some way of letting the child repair their computer, or at least learn how to.