Last year I was able to order as soon as I got up on Thanksgiving, so it was active by about 8am. Don't know exactly what time because I wasn't shooting for one of those sure-fire sellout items. This year I will be, so I think I'll stay up to see if it goes live at midnight.
ETA: I am apparently the queen of lousy timing - I just bought my kids laptops for Christmas, which will put me over the threshold for elite status but not in time for the Black Friday pre-sale.