While I'm alright with the basic premise, I think it does still require more enforcement than is given.
Alot of it depends on the child too, some it won't work well at all for... I know I myself would be HORRIBLE to be unschooled as described there. I'd never learn anything unless I'm forced to.
I WANT to learn... but I won't do it unless I have a reason to do so. Just hoping I magically pick up on things doesn't work. Even expecting me to learn stuff on my own won't. I just don't do crap all if I'm left to my own devices, I NEED school to teach me stuff XD
There's exceptions to every rule though; some will go out of their way to learn stuff simply so they can. Most children don't do that past a certain age. Some may but it's not something that's a good idea to test out at random.
If it WORKS though, I imagine it'd work better than normal, as stuff learned would make more sense and would be more likely to be remembered and understood completely rather than just forgotten, like most school stuff.