I have a few thoughts on this subject from a man's (and father of teenage daughters) perspective...

I would be very wary. My sister married two bums (very young and immature men) to whom she has had 3 children. The first husband is now in jail in MI and the second is zoned out on a couch on morphine, dopamine or whatever "ine" he can get his hands on. Neither one assists her financially in the raising of their children. Both "tried" for a while to be decent fathers.

It is good that the bum is changing some and that he now holds down a steady job. But don't be too optimistic. And don't give him "too much" credit. I am sure that he wants a job cause he needs some money too!

I know they are young and that time has a way of making all of us grow up to some degree. He just needs to accelerate the pace. You(HE) is a "DAD" now, with all the responsibilities that go along with it. It is time to "give up" the MySpace and adolescent ways. Hope he continues along his current path and as you say, "grow up together" for the best interest of your daughter, his baby and himself!