Okay, lots more good information to digest.
My initial thoughts on reading everyone's responses:
1. I see the value in starting new threads..I lost this one for a while, and only saw the new handwriting one.
2. I feel much better equipped to answer concerns over bullying and social issues. I do agree with many of you that parents need to stay very in tuned to these issues.
3. I am a little confused on what seems to be a majority opinion on possibly "one skip at a time" or "baby steps". This is at the heart of our angst over starting school. My premise is this, and perhaps I am wrong: Why spend the huge amount of money on a private, gifted school so he can "formally" begin his education opposed to preschool where he would be if we kept him in the public school system, if the placement is not correct?

Is it any better to be unchallenged in 1st grade then it is in pre-school or kindergarten? If a child already knows all the material, isn't the only option at that point to either send them strictly for socialization and not academics or home school?
I ask this with all sincerity. I respect your collective experiences in areas we are just beginning to explore.

I am fearful that if we don't provide a challenging environment his incredible spark and quest for knowledge will be extinguished like so many other gifted children I have read about.

To answer some questions posed earlier - the school has already agreed, in fact, suggested the 1st grade placement. They are a gifted school but their criterion is a bit more relaxed than the public school gifted program. You need a score of 130 on an IQ test in any of the one areas, your full score does not need be 130. Also, they have a preschool and 75% of the students in preschool, which is does not require IQ scores for entry, are accepted into the regular school.

They do say that their curriculum is one year ahead of the public school. We have taken that into account when looking at what curriculum our son is ready for and the achievement tests place him there as well.