Why is it important that it's "in the box". You can have a html page started with a link to foundation and be doing a progressive grid layout in less than a minute. If you don't like their grid implementation use one of a dozen others. I'm guessing you used pre 3.0 twitter bootstrap. The latest bootstrap (I don't know how good it is, I have mainly used Zurb Foundation) is supposed to be much better at supporting progressive grids.
