>I'll concede a bit, and say that this functionality could be useful, I just don't think it should be automatic. I think maybe a good compromise is the way that IE handles it: allow the user to resize by setting a menu option.

I think you've hit upon a good idea. Have maybe 5 different fixed resizings available, independent of resolution. All you have to store in the user settings is one value. And no concerns about picking up resolution changes while your app is running...and gives user pretty wide flexibility in sizing...and is sort of close to whatever standard there is for this sort of thing, at least you can point to IE if someone inquires why you did it this way.