I believe you can make reservations now but room pricing for that period won't be available. I'm not sure when that comes out but maybe someone else can help with that info.
You need to start making your reservations now...that way..you can have good rooms ect. (We always made our reservations a year before)
Also, Look around the interent and keep calling back the reservation people,to see if you can get better deals! I got a lot of good deals of the internet.
We're going this December and staying at WL too! We're going the second week of December and I always hold out making reservations until about three months before to see if we're getting any codes in the mail. If you're going during a busy time-like around Christmas-I would make them now.