Sure do! www.disneycruiseline.com
Look toward the upper left of the home page for a drop-down box listing "Ports of Call".
Basically, the Magic handles all the 7-night trips, and they alternate destinations; Eastern Caribbean (St. Martin, St. Thomas, Castaway Cay) one week and Western Caribbean (Key West, Grand Cayman, Cozumel, Castaway Cay) the next week. They do have some trips with alternate destinations (St. Croix, for example) coming up - - see their website. Departs Saturdays @ 5pm, return the following Saturday around 5:30am.
The Wonder handles the 3 and 4 night trips. Usual itinerary is Nassau then Castaway Cay, but they too have some alternates that include 2 stops at Castaway Cay. Cruises depart on Thursdays and Sundays.