I saw mention of a Fall Mega bonus in a Miles Link email:

Bonus Corner
Marriott MegaBonus
Marriott Rewards members can earn up to 10,000 bonus Marriott Rewards points when you pay for hotel stays with your Visa card from Sept. 23, 2007 through Jan. 18, 2008. You can earn 2,500 bonus points for every Visa-paid stay, beginning with your second stay. Register online for the bonus or call 888-MARRIOTT (627-7468) during the promotional period. The maximum mileage earned during the promotion is 10,000. Stays that occur during the promotional period, but before registration for the promotion, will be retroactively counted toward the bonus. Some Marriott Rewards members will receive a different promotional offer via e-mail and will only be eligible for the offer they receive.

But nothing official from Marriott, usually I get an email from them touting the promo.

BTW, pretty lame IMO. Hopefully my targeted promo, if it even comes, will be better?