Actually, I discussed this topic already, but I'm mentioning it again here since it's thematically related to the other Start menu articles.
I'm told that there have been a few tweaks to the rules for Windows Vista. Some installers set the time stamps on the program to match the time stamp of the install media. This makes for pretty directory listings but means that the Start menu fails to recognize the program as new. To address this, the Start menu also takes the creation time of the directory containing the program into consideration when determining which programs are new.
Second, a program that appears in the pin list will not be marked as new, since that would be pointless duplication. (This is only an issue for the "chameleon" pin list entries like "Internet" and "Email" which track your current default Web browser or mail program.) And third, the grace period after installation has been extended from one hour to five hours. This gives computer manufacturers more time to install all their shovelw^H^H^H^H^H^H^Hhigh-quality added-value software.