I caught this via ActiveWin today: Tommy from IMSafer Nerd Blog decided to give Windows Vista’s Parental Controls a closer look. He outlines the Parental Controls features and explains what parents can do with the features. He puts in bold his opinion regarding each Parental Control feature, and although he's rather critical of the breadth of control afforded parents, I think he's off base and that parents will ultimately grow to appreciate and use many or all of the available controls, especially when they work together to better understand them via online forums and communities. He does seem to like parents' ability to log everything their child is viewing, downloading, reading, etc. He also mentions the ability for third party developers to tap into Windows Vista’s Parental Controls API, which is another key aspect of the functionality that I think will ultimately make these controls very compelling for a large number of parents.
Take a look at Tommy’s Windows Vista Parental Controls Review.