I read Malcom Gladwell's book, he describes things in which there is clearly a well supported scientific understanding of. I agree "10,000" hours is a bit arbitrary, but with careful observation it does happen to be the amount of time on average it takes to learn something to that high of a level. That 11 year old kid probably practices a lot more than 2 hours a day, I'm not sure why you think that's not possible. I understand there are more factors at play than just putting the time into it. Ideally he'd need to be practicing efficiently, and have a brain well suited to learning that type of information, and be in an environment that nurtures that type of behavior. It's still a physical process of learning and growing the brain. I don't think I could ever truly understand the brain of a genius of that level, and he probably doesn't understand it either, but there is work involved to getting to that level.
Pianoworthy,I'm quite certain he practices two or more a day. To get to 10,000 hours he would have to have done that SINCE THE DAY HE WAS BORN. Somehow I don't think THAT is possible.