Very Merrytime is SO much fun...lots of activities from making ornaments to decorating gingerbread cookies. Tree lighting ceremony in the atrium with the characters and Christmas carols, Winter Wonderland Ball with Santa, Mrs Claus and snow in the atrium. The ship is beautifully decorated with a huge tree and gingerbread house. Characters are decked out in their holiday finest. Families getting their photos taken in ugly Christmas sweaters and/or Christmas pajamas. It's a week long celebration (or in your case a 4 night celebration!)!
Also you can order special holiday decorations that will be in your room when you arrive - and also a special Christmas blanket and pillow to take home.
If you can, spend a day at WDW for Mickey's Very Merry Christmas Party and another day at Epcot for the Candlelight Processional. The parks are also wonderfully decorated for Christmas.