I am just posting a reply because I wanted to hop on this thread. We are doing an Eastern cruise in Jan '03 and our DS will be almost 6.
For what its worth, we spent most of our 3-day Wonder Cruise (we did a land-and-sea at the Poly) in the Mickey Mouse pool. Its all DS talks about now and with two days at sea, we may end up there again. However, I am interested in hearing about excursions for kids that age.