There are a couple sites that have the Black Friday ads listed early.
I do take advantage of Black Friday deals but I do it in an unconventional way to take full advantage of the sale prices but not have to venture out early and fight the crowds.
First, I check out the ads ahead of time, like the links you mentioned and make a list of what is on sale where, at what price. Then, I go through that list and pick out anything that can be purchased at wal-mart and go buy those items there on Black Friday. But you don't have to go early, because they are items that are not on sale at Wal-Mart, just at the other stores. Then, when you get to the register, just pull out your other ads and tell the cashier you are using their price match policy. As long as it is exactly the same item, you will get the lower price.
But...If there are really great deals on items that you cannot buy at Wal-Mart, I buy it on Tuesday or Wednesday of Thanksgiving week and pay full price. Then, sometime on Friday, usually as late as the sale goes to avoid crowds, my husband and I get hot drinks and drive to however many stores. I take my receipt in to the customer service desk (usually not busy at all, everyone is at the registers) and get a refund (price correction) of the difference because most stores offer this service if the price goes lower within 30 days. My husband takes the car in a circle around the parking lot (avoiding having to find a parking spot) and then picks me up and we are on to the next store in 5-10 minutes.