I would put down my cheerleader pom poms and take this time to work on myself. Go to meetings, read Codependent No More all the stickeys, Cynicals blog and more.
You are codependent,we codies get all excited when we see any glimmer of hope, I would be causiously optimistic and leave it at that. His journey has just begun, detox is a baby step, he has years of recovery ahead of him....IF that is what he chooses.