Forgive me if this has been posted elsewhere but I just checked the
Marriott Gift card site and the 10% bonus or 10 points/ dollar bonus are back through 1/8/2012
Note that you cannot combine the offers (I tried and it wouldn't allow it).
10% Bonus - type MMF into the promo code box and an extra 10% will be added to your card value
10 points/ dollar - put your MR # in the appropriate promo code box and 10 pts/ dollar will be added to your MR account up 25,000 points.