I would definitely bring a stroller. It is easy to get around the ship with a stroller or baby carrier. If the baby is of crawling or walking age, you might enjoy taking the baby to Camp Carnival during the times, where they let under two's use the facility with a parent.
Obviously it will be a different cruise experience with a child, but certainly can be just as enjoyable. Consider bringing along a grandparent, aunt, etc. , as that will give you and your husband some alone time.