Just made a reservation for WCT and got the scoop... CM said ALL of this is subject to change, including times, prices, etc. Right now WCT is taking reservations in time slots for two of the showings- 4-6:30pm and 6:30-8:30pm. Basically you eat your meal and when you leave they give you a ticket for WOC. The catch here is that they MAY RUN OUT OF TICKETS. There is no guarantee that you will get a ticket. They will take walk-ups for the WOC dining package at WCT also. If you do get a ticket, you will take it to a special area to turn it in. They don't know where it will be or whether it will have any seating.
Ariel's Grotto will be EXCLUSIVELY for WOC whereas WCT will not. There is still no guarantee that you will get a ticket at AG but chances are pretty good.
All reservations are on the honor system, there is no payment taken until you dine. They do ask that you cancel 48 hours ahead but there is no penalty.
The CM was very nice and emphasized that they are still getting info and have lots of unanswered questions. I took my chances and booked a WCT 5:00 seating, knowing I can always change/cancel it. We shall see!