The folks over at Fatwallet have deduced the schedule of upcoming wish certificates from the American Express Wish List Promotion. Here it is (the numbers after the colon indicate quantity):

12/09: 1333, 1200, 834 —> (Best Buy, Bed Bath & Beyond, Overstock)
12/10: 1200, 1125, 1333 —> (Brookstone, Toys R Us, Best Buy)
12/11: 1125, 1333, 1125 —> (Amazon, Best Buy, Toys R Us)
12/12: 334, 500, 1125 —> (Home Depot, Blockbuster, Amazon)
12/13: 747, 1000, 1333 —> (LandsEnd?, Borders, Best Buy)
12/14: 1336, 1125, 1125 —> (Best Buy, Amazon, Toys R Us)