I have been married for 8 years. As for the graveness, I haven't seen any more or less failed marriages than anyone else. It's pretty common. What I have noticed is that the ones that fail are the ones that took the commitment lightly or treated it as something trivial. Yeah, we just thought we'd get married cause why not really... -Hey, sometimes that works, but more often than not it takes some real work and more than anything good communication skills to make a marriage work in the long run.

Having a child has been great for our marriage. We made sure our marriage was in a good place prior to having a child though, something I would HIGHLY reccommend to anyone reading this. Like anything worth while in life it takes work. That's all. I really enjoy it though. We've been together for nearly 10 years now and just the other day we both played hooky and went to see an afternoon movie. This is something we would have done when we first met too, the only difference now is that we went to see Despicable Me 2 and had a 2.5 year old with us :)

edit: For the record, I'm not trying to be preachy or seem like I know any more about this than anyone else that's been married. These are just my observations. Also, from your enthusiasm and genuine curiosity about what others have experienced, I would gladly put money on you and yours having a good go of it!