dazed, you posted your son is accepted to enroll in the Fall of 2012. Did you mean 2011? I have never heard of a college accepting applications and giving acceptances 16 months before enrolling, but maybe things are changing.
If this is 2012, then I think you and your son need to realize the staff is just likely beginning recruiting for 2012. Yes, your son should call or, maybe even better, go to the school and meet with the coaches.
If your son is accepted and this is the school he is attending, playing baseball there may well be dependent on your son being very proactive.
As justbb says, call the coach, go visit the coach, ask to be invited to the camp, show that interest. Your son has nothing really to lose if this is his college.