and in any case they've most likely fixed their box-model screwup in IE 7 so your point is moot. when people start using IE7 en masse you're going to be left with websites that look completely wrong on 90% of the worlds computers.

Even with the JavaScript to sort out the width problem, the ultimate code doesn't even come to half what you suggest

don't take this the wrong way but you seem to have a lot of weird perceptions...the first and most prominent being that you seem to think Javascript has anything at all to do with page layout....JS is for adding functionality like popup menus (although these are possible entirely in CSS anyway). If you rely on Javascript for layout then you're gonna have lots of problems because a lot of people simply have Javascript support turned off.