I'm surprised; I have never heard of that youngster! I found some earlier footage (like only a year...LOL! He also does Hendrix's Purple Haze, Clapton's Crossroads, Michael Jackson's Beat It, etc.) and the guitar is as big as he is! He actually plays that same song in the clip I saw, but he doesn't play it as well as he does in that Ozzy clip (I also found a better recording here: YouTube - Ozzy Osbourne Crazy Train LIVE HD @ BlizzCon 2009), though it is still spectacular given his age. In just a year or so, his improvement is quite evident.
Although I still think his guitar playing lacks a bit of depth and feeling, he is very young and that will undoubtedly come to him with age as he will certainly improve his skills and get better acquainted with his instrument. He is indeed an extremely talented and gifted guitar player! Simply stunning to watch him play!
I have to say I can for sure see the inprovement in the three years of the two videos. Give the kid another 4-5 years and he is going to be the next Joe Santriaty ( Not to sure how to spell his name) This kid is going to go somewhere with that tallent and Ozzy getting his name out there man he is going to be something big I think.