EDIT: we do normally not fight over the xbox but I could see this starting a few.
360 Fall Update To Include A Game Timer?
Anyways, more info about the timer. It is said it will be password protected (an obvious thing or else little kids could just turn off the timer). Different sources have different info about how the timer will work. Some say it will turn the console off once the time is up for that play session, others say it actually clocks the time the child is playing games. The former seems more likely to me. Or perhaps it can do both? Who knows.
More news as it develops.