Ania,
Your son's score is very impressive, especially on math side. I would echo Trinity's suggestion that he does it again before age 13. He has real good chance to get at least math score to be over 700. With that he will qualify for CTY SET (study of exceptional talent). It is a quite exclusive club (so exclusive that few people know it or care about it). But there are some perks with joining SET (free magazines, newsletters, bragging rights, etc). The rumour says that some top universities even track these SET kids. Not sure how true it is.
If you want to know more about SET, check it out.
http://www.jhu.edu/~gifted/set/index.html
