Forum member JasonX1 at the official Xbox forums has spotted some Fall Update information found on the back of a Guitar Hero III keychain leaflet.
The leaflet's back mentioned a "Family Timer" that can be set by parents to limit their kids' daily and/or weekly gameplay time. We've already heard about the family timer about a month ago, but the pamphlet is the first "document" to officially mention it.
"There is some information coming out via a pamphlet that comes with a Guitar Hero 3 keychain, that the rumored Family Timer, which lets parents limit how much time their children can spend playing their Xbox 360, will be available in December 2007", JasonX1 wrote. " Now, considering most major Xbox updates are done in either the Fall or Spring update, this feature would probably be a part of the Fall update. This could be an indication that the Fall update will hit in December. Fall does carry into December, after all."