I would also council matching your expectations to your childs: I played baseball in college and was understandably hoping my son would want to play.
I did all the right things, kept it fun, etc. He was very good right up to the day, he was 10, when he decided he really didn't want to play baseball anymore...he thinks it is, "boring".
He prefers martial arts, music and outdoor activities (fishing, shooting, camping), all of which we support completely.
It was hard not to push for, "one more year", etc., but I didn't and I think it was the right thing.
