I agree with everything RockysWoman said here. Having just done this three years ago with four (at the time) dogs, everything she said holds true.
The reaction of our four ranged from interested to couldn't care less. But they all were very keen on letting me know the baby was crying (as if I couldn't hear it myself!).
The most delicate time for us came when Ethan started walking, not when we brought him home. Our two oldest basenjis, which had lived many years as a 'child free' home (and are a little more high strung than our subsequent basenjis) were really nervous when the baby would approach them. We made areas were they could retreat from him, and in time they became used to him. At this point, they are very comfortable with him, love the fact that he sneaks food to them, intentionally and not, and even try to initate play with him (something I thought I would never see two years ago). Our younger ones have been totally comfortable with him all along, and they enjoy him immensely!
So, it will be fine, as long as you continue to let Captain Jack know you still love him. Make sure you reinforce 'kid being here means good stuff happens'…don't reprimand him for interacting with the baby, or he will think 'this baby is nothing but trouble'.