As of December 1st, 2008 all Marriott full Service properties have been told they are no longer allowed to give their Platinum Guests vouchers for breakfast on the weekend when the concierge lounge is closed.
This is devaluing the benifit of being a Platinum member and if anything makes staying at a competing brand more attractive since most reward their elete members with breakfate on the weekend.
Have you actually verified this to be the case, i.e., no comp breakfast on weekends for platinum. My next weekend stay will be middle to this month in the DC area, Fairview Park Marriott. They've always comped breakfast for me and my wife on weekends, so it'll be interesting to see if that's been discontinued. I'll advise.