You can't book online yet because prices and seasons have not been released. If you call to book, Disney will tell you that you will be charged a one night deposit based on 2007 regular season rates, which will then be adjusted up or down to account for the season and the 2008 rates. If they tried to do that online, it would be difficult to ensure that the guest understood that the rate online would not be the actual rate during their stay (since prices will change and you might not be going during regular season). You can still book a room-only for 2008 now, and CRO will send you an updated confirmation with any additional amount due (or credit applied to your stay).