There is some rumor saying that Yi was born in Oct. 1984. The majority seem to indicate that he is either born in 1986 or 1987. And Yi is listed as 17 seven old when China submits the information to the Olympics.
What you want Yao to say about Yi when asked? It's just plain simple that there hasn't been anyone that tall with that kind of athletism in China basketball. Wang Li-bing of 20 years ago might be close, but he was only 6'7". The problem is there are so many 6'10", 6'11" guys in NBA, who are more athletic than Yi. So yes, he is special in CBA, but is just ordinary as a NBA prospect. So, let's just wait a couple of year before jump into any conclusion.