K-Mart were supposedly punished with a fine and were not allowed to sell Gears 2 when that was released, after certain stores broke the street date and sold Fable 2 early. I can't confirm anything about the fine, but i do know that one store (and it was one of the stores in Victoria which someone had scanned and posted the picture online here and other forums) still sold Gears of War 2 at the same time as everyone else!!!
So i'm not sure if the punishment where they weren't allowed to sell GOW 2 straight away, was serious - or just a PR exercise.
It wouldn't hurt to try and see if Big W did sell it early, i know it probably wouldn't result in us gamers leaving with a copy of the game a few days early. We'll have to go to ground and put up with many threads where the subject is "have they broken street date yet ? "