This is the information from Mousesavers...
Get 25% off a Platinum Package when you stay January 4 through June 30, 2009. I have never before seen a discount offered on this ultimate package!
The all-inclusive Platinum Package includes accommodations at a Disney Deluxe resort or a select Deluxe Villa (DVC) resort (Beach Club Villas, Boardwalk Villas or Villas at Wilderness Lodge), plus three meals and two snacks per day, unlimited recreation and theme park tours, a spa treatment, an evening at Cirque du Soleil, a fireworks cruise and lots more!
With this offer, you really do get 25% off the entire package! For that reason, it might make sense to load up the package with 10-day tickets and get the Park Hopper, Water Parks Fun & More and No Expiration options, since you're getting 25% off those too -- an unprecedented discount on tickets. If you stay less than 10 days, you can alway use the remaining features on your No Expiration ticket during a future visit.
Availability is limited: some dates and resorts will be not be available. Reportedly April 5-18 are blacked out completely. You must book by 2/15/09.
See Mousesavers for how to book though...
HTH!