TPM, yep I agree on MPH not being the only indicator for any level. Just a number, reality is he sits 84-88 most of time, and has multiple (4) pitches he throws well though I am not sure how well from a colleg point of view. Anyways, for him the D1 experience is just as much if not more about the campus than the status of playing D1. He likes the size campus that is generally D! at least in Ohio 15-18k students. There are a lot of them here, roughly 10-12, the D2 and D3 tend to be much smaller here. But for instance he had no real interest in Ohio State which of course is a D1, but huge. worked out well in that they had not interst either 
It,also, happens that these are all state schools (except 1) and make it much more affordable for our family.
We are taking a couple of college visit that we are setting up in next couple weeks to the biggest D2 and 3 colleges we can find, regardless of baseball, although they have shown interest but I think they thought he was going D1 so have just been on the "we are interested if you are list of thiers". They all have his major which of course is first on the list 
Your son will be fine and he will discover someone who really wants him to come to play for their program and will make him feel good about himself.
If it doesn't happen now it will happen.
FWIW.I have found that many parents/players who post here do not have sons that commit as early as everyone thinks that they do. I don't know why that is but it is something that I have found interesting over the years. I think that a lot of people coming here for answers end up putting a lot of thought into it and recognize that there is so much more to it than just saying yes.
Good luck and keep us posted.