We booked Embassy Suites at Miami A/P for our 12/4 cruise. I, too, was concerned about transportation and did not want to use cab service.
If you look at their web site, you'll see that they offer free shuttle from A/P to hotel, but they also have a "special" for transfer from hotel to pier or pier to hotel. It might be considered expensive - but hey: they provide a great breakfast and host a lovely 2 hour manager's reception each evening. I know we could do better on Priceline, etc. but we like ES.
(We stayed at an Embassy Suites in San Diego in May and while they said they only provided transfers between the hotel and the airport - they kindly transported us to the pier free of charge.)
Yes we do and we are coming all the way over from the good old U.K.!
We are staying overnight at The Regency Hotel, 1000 NW, 42nd Avenue, FL33126. This Hotel offers a free shuttle service from Miami International to the Hotel and then a free shuttle service from the Hotel down to Miami Port and is inclusive within our B.A. Air Ticket price.
For us it is ideal as we do not want to rent a car for one night after having been flying for 9.34 hours etc and using the shuttle will make life alot easier and straightforward.
Hope this info is of help to you - from across the pond.