dear d00ds: This isn't math. The games have to be played. The only form of savant that would help him in this instance would be being a savant at seeing the future.
There's a study (obviously a little far-fetched in a lot of people's minds) done by a psychiatrist whose a professor at the University of Wisconsin that allegedly found links to ESP in some autistic savants.
The professor that wrote the study is pretty well respected in the psychiatric community and is an expert on savantism. So if you believe that sort of thing (not saying that I do), then it isn't necessarily impossible to believe that the kid didn't just get lucky.
It's also possible that the kid just knew his crap and was actually able to predict each game correctly from his knowledge of the teams (his family said that he memorized things so ridiculous as the height of each player on each team). If you just gave some person with no knowledge of the teams a bracket and had them fill it out then they would have a 1 in nearly 13.5 million chance to get it right.
Or it very well may have been just luck (or the family editing his bracket after the games were played), which is what my instincts would have me guess. Regardless, I'd love to hear what the kid has to say about why he picked each team in the games that he did.