The last 2 years they have extended discount to include Easter week (I am a teacher and travel time is limited to breaks).
What usually happens at Easter is the week is always blacked out of every deal.
About 45 days before (after final payment is due) they typically open the window. In 2009 we went Easter week with the 4/3 deal and in 2010 we went Easter week with a 30% room discount.
You have to watch for it to open up than call and request a refund.
The catch is they usually open up AFTER the 45 day window of Easter week so you have to be willing to pay rack rate and to actually pay it. Once you are within you 45 day window full payment is already done on package. We are always willing to pay rack rate and very happily surprised with a deal comes along.
Good luck!