I will be getting married on the Wonder sailing on Sunday. I can answer some of the questions so far.
As I've mentioned, we're on the Disney Wonder sailing 11/11/07 and we have 13 guests attending. After a few days of calling, we finally got in touch with the Disney Wedding Coordinator on 2/9/07. Even though it was more than 9 months in advance of the date we wanted (11/25/07 - our dating anniversary), it was already booked. They only do one Castaway Cay wedding per sailing, so I suggest booking as early as possible, especially if you want a specific date. We chose our alternate date and booked it on 2/12/07. You MUST have your cruise booked before you can secure the wedding date because the wedding package gets added to your existing reservation.
For us, the booking was easy because we are paying for all the guests to attend. I used a travel agent and got a group rate (8 rooms or more qualify as a group). Since we're booked as a group all the reservations are linked. I'm pretty sure you can book as a group even if more than one person is paying. Even if you're not a group, I think you can contact the cruiseline (or your travel agent) to get the bookings linked so you will be on the same dinner schedule & rotation. They CAN NOT confirm that everyone will be seated at the same table or even near each other. The only thing they could confirm is that you will be in the same restaurant. I'll post again after the wedding on how that works out.
You can have as many guests as you'd like. Eight guests are included in the cost, unless they've changed it since we booked. Any additional guest will be charged $10 per person to cover the extra cake and champagne.
They told us that right after the ceremony the guests will go to Palo while the photographer takes us around the island for pictures.
I definitley plan on coming back here to post about the experience and to answer questions. One thing I found quite frustrating throughout the experience so far was that there was VERY little information about Casaway Cay weddings to be found anywhere, especially in the early planning stages. More recently it seems a few people have come out of the woodwork to talk a bit about their Castaway Cay ceremonies, but there still isn't a whole lot of information. I'd like to help future brides & grooms or potential brides & grooms to decide if a Castaway Cay wedding is for them.