You better call now. They start taking request two years out. Remember that making a trade through II is not like a reservation where you call and see what is open. When you call you must give them dates that are open to you and your preference of resorts. Then it is submitted and you wait for a match. You will be quite lucky if you get a match right away. The more time you give for the search the more likely you will get one of your choices. I know that Dean can explain this much better than I can.
I called about a month ago to trade for july and august 2009 anytime in the summer we could go there was no match they are searching for a match. I chose two different resorts. I gave them about a six week time frame. I chose the Atlantis or a resort in San D hope I will get a match but I do not no what my chances will be.