While this article is rather superficial, it actually raises some valid issues. I actually belong in the camp that does not support acceleration based solely on intelligence. Achievement, physical skills, and maturity are relevant as well.
I was accelerated as a child (young 4 year-old with first graders who were 6 and 7 years old). While I understood the rationale for the acceleration and it may have been the best fit at the time, I don't think that overall the acceleration was necessarily the best way to go. I felt too much "apart" from the other kids and really did not have the requisite maturity, which got me in trouble with certain teachers. I ruled out the possibility of a grade skip for DS9 when it was suggested by his second grade teacher but I do have him subject acclerated in math so that he is in Pre-Algebra as a 4th grader. To me, I see some value for DS to be among his age peers.
