I found this Boston Globe news article rather interesting. Although it doesn't specifically make any reference to stamps, I can see the images of people depicted on stamps as being affected by such laws -- many are already -- so it certainly will have impact on future stamp subjects as well as any other marketable items with celebrities names and/or likenesses on it:
http://bostonglobe.com/ideas/2012/0...K/story.htmlAn interesting legal issue, to say the least.