We sailed on the Inspiration the week after Thanksgiving a few years ago and it was decorated beautifully for Christmas, excellent photo ops! We're sailing on the Bloggers Cruise on Dream 12/3 and I hope it's already decorated. I plan to decorate the house before we go, I LOVE the season and since my son is allergic to Christmas trees, we have ours ready to go in the basement.
I agree with the best gift being family. About 4 years ago, we started giving our kids a cruise for Christmas, but we don't sail until February break (5 kids, so it's more affordable).
Hope everyone has a great time with their families onboard!