The variation I keep seeing today is sites that lose any left margin at all when the browser is less than 1000px wide (or 930 or whatever magic number the designer had in mind that week).
It's pretty special seeing text butted up hard against the left margin. I'm glad the proliferation of web standards has advanced to the point that this is acceptable!
Thank you for saying it. This "fixed-width-in-pixels" thing that has taken hold completely baffles me.