That's okay. It sounds like you need some sleep! :)
How have your holidays been going so far? I've only done some minor revision but I'm hoping to do some prelim maths + extension 1 tomorrow. I borrowed Cambridge 3U HSC from the library and thanks to the Christmas & New Years holidays it's not...
I usually try not to eat anything before I sleep. Sometimes I'll play on my iPod Touch until I feel tired or read a book. As long as you're getting the right amount of sleep (7-9 hours I think) then you'll be right. Just gradually adjust it before school starts.
I only like the new notification centre & quick access to the camera. I found reminders pretty useful too but I wouldn't see myself using that very often.