The crap wares they loss-leader the unwashed masses into the stores with are always mediocre at best - so if you're buying something like a flat screen TV, chances are the specs are stripped down and it's usually the lowest spec model in a line - so look before buying. I'd much rather spend 100% on a good TV than get 50% off a crap tv.
Based on the black friday junkmail i've seen so far, this year is a marked shift from the past and nothing great is being offered as sacrificial loss leaders. Obviously the stores are struggling (i.e. Circuit City closing stores and going bankrupt) compounded by the fact they know there will be a dramatic decrease in foot traffic and shopping activity due to economy.