Well, my almost 7 yr old boy/girl twins (7 on Valentine's Day!) go to bed at 7:30 sharp! They may stay up till 8:30 on weekends. They get up at 6:15 am for school.
My 11 1/2 yr old son (6th grade) goes to bed at 10, and is up at 7:15 for school. He usually stays up till 10:30 or maybe 11 on weekends.
These are good bedtimes for us because (1) nobody ever acts cranky (due to lack of sleep!) and (2) for the twins, although 7:30 might seem early, although they might complain about bedtime, they are always asleep within minutes when they go to bed. They are exhausted from a rigorous day at school.
I feel for our kids, all of them. They really have it tougher now, in school, than any of us ever did.
Suzanne