Today only those who also had Walt Disney World hotel reservations were able to book their trip.
Those staying off property on Annual Passholders with no hotels needed will need to wait a few days.
On the plus side, while there appeared to be a system bottleneck of guests trying to get in to book, it seems that maybe the actual booking isn’t that big a deal.
I haven’t seen any reports of the first few days filling up or people not able to get the dates they want, and it looks like there is still availability across the board, though that certainly may change as more people get in and book.