It sounds to me like you are already taking the best approach with your DS. I am of the same opinion as your DH regarding testing. In your particular set of circumstances, you may as well wait until when talent search starts in 2nd grade. In the meanwhile, keep providing the enriched environment and follow your DS' lead as to when to offer more structured learning opportunities like CTY, EPGY, ALEKS, etc.
For what it's worth, all three of my children really enjoyed kindergarten and did not focus on the academics. However, I am not sure but I don't believe any of them were actually "reading" before entering kindergarten. The reason I am not sure is because I did not teach/test them and really focused on promoting other kinds of learning and none of them were enrolled at "academic" pre-schools. For my DYS DS, he was able to read a 1st-2nd grade level book that I handed him a couple of months into kindergarten, but I have no idea at what point he actually learned to read. At that stage, he still prefered that I read to him and explained to me that he did not enjoy it as much when he was doing the reading because the process of reading distracted him from the enjoyment of the book. That may be the issue with your DS so I would follow his preference. DS was at 5th-6th grade level within a year and must have gotten past that distraction/enjoyment issue well before then. Similarly his twin sister (borderline/almost DYS level)did not start reading 1st/2nd grade level books until winter of kindergarten and jumped to 3rd/4th grade level before 1st grade. Even my oldest DS, who only tested MG with 2E issues, learned to read fluently in 1st grade and was reading 3rd/4th grade books in 2nd grade.
Children are such sponges at that age. I truly believe that if they are not focused on formal academics, they are absorbing other knowledge/skills by leaps and bounds. Bottom line, with two PH.D. parents and in the absence of medical issues, it is unlikely that your DS will not be somewhat gifted.
