You've mentioned he's had a few nibbles, unofficial visits, etc. What type of feedback is he getting from coache's that he has spoken to? Did they indicate they see him as a potential 2way and did you get a sense as to where/how they think he would fit in their program. Are your travel coaches in a position to give you feedback on where they see your son. I would try to get as much candid feedback from folks who have seen him play as possible. What you hear may ultimatley help you determine what are appropriate target schools.
You're getting very good advice from others on how to proactively push this along. It's important to try to target schools he feels comofrtable with athletically, academically, socially and finanically.
I can't stress, however, how important it was for my son to not only have a college recuriting plan, but also to keep that plan as sepearate from playing baseball as possible - Got to stay focussed on improving, staying positive and making the most of every opportunity in front of an audience. It may feel like its moving slowly, but if he develops a plan he will have opportunities over the summer and he will need to make the most of them.