We've applied to the DYS program recently and are waiting to see if dd has been accepted or not. She is also 7 and in 2nd grade, like your son. Based on everything I've read, and the response from the ladies here, the YSP sounds like an excellent program. DD also scored well on the WISC IV and is doing accelerated work in school. She isn't a child prodigy like you described (nat'l awards, piano, math etc) but there's no question that she's PG.

I think your son would benefit from the program, especially if he has no acceleration options.