I have had a few problems juggling family life and gaming so far.. But most are overcome easily when you take WoW in moderation and realize that family is far more important.
I also have a wife and my son is 14 months old now. I took the first week of launch of work expecting to be lv40+ there, but it turned out my son got sick on the last days and the wife and I during the last weekend.. So I made it to lv30 or so after 1 week, a lot lower than expected. As of right now I am ½ a level from 40, only playing a bit on the weekends and on the evenings when my son is asleep. My wife is understanding that I am pushing to 60, so after that I will be spending more evenings with her and leaving me with 3 - 4 evenings worth of gaming only which should be more than enough to both sustain a main and dabble into leveling an alt.
I am more than happy to keep my gaming to a minimum once I have a main, but I am pushing it a bit extra the first month or so here so that I dont miss out playing with guild and friends.