Lots of stores have them, they just don't call them "Boxing Day" sales. They use "After Christmas" mostly - just watch the news and you'll see shopping madness the day after Christmas, with no mention of boxing day. I had a neighbor growing up that always had a Boxing Day gathering at his house, for all the neighbors. For all intensive purposes, Boxing Day doesn't really exist in name here.
I wouldn't hold my breath on vendors holding special sales, but with the promo codes and such, there are always great deals to be had. I think we've gotten spoiled with the "extra" special deals, personally