The discount is available through May 12th,which is this coming Saturday according to our calendar. There is no word on whether or not the $50 haircut applies to higher capacity models. Earlier this year, Target offered a $200 trade-in for the Apple iPhone 4 which essentially allowed owners to trade up for free to the Apple iPhone 4S. Of course, that deal required you to sign a 2-year pact, but ended on March 3rd.
source: 9to5Mac via electronista