I would also be surprised if there were any additional major changes for 2007. I remember Chris saying that they will give more warning for major changes, unlike what happened with the category changes this March.
If past history is any guide, I do not expect Marriott to make large devaluations, unless they decide to get rid of the travel packages. That would be a major loss. Gradual devaluations will keep occurring as the supply of points and room rates keep increasing.
One thing I have noticed is that Marriott is putting more materials in hotels to get people to sign up for Marriott Rewards. At the Fairview Park Marriott, they have a placard about the rewards program by the elevators on the 16th floor. They also have more materials on the rewards program at the front desk. The placement of additional material has occurred in the past two months or so.