We just got back from travelling with our 8 months old twins. We had a brilliant time and loved the cruise and especially all the interaction they got with the characters. Mickey mouse got down on the floor playing with them etc and whilst they don't remember it I always will!!
The only thing I would say is beware with the nursery, I had only read good things and trusted them fully. However they were in 4 times for 2 hours each and twice we got phone calls to say they had head injuries (one time they couldn't tell me which one of babies it was that had a head injury) and then on the last visit they used formula milk which they knew had been left too long to be safe to feed and it made my boys seriously ill, we ended up phoning 911 the day we got off the cruise and the boys were hospitalised. They are on the mend now but I just thought you may want to be aware before putting your child in the nursery.
Like I said the rest of the cruise was amazing before they got ill and I would definitely sail with babies again.
Only other thing to be aware of is that not all strollers fit through the doorways to your cabin. Rest of the ship I was fine with my double buggy even the corridors with carts etc but I know other people said their single strollers wouldn't fit through their stateroom door. Just a heads up incase your baby will sleep through dinner like ours did in their stroller.
Have a fab time!!