The thought of XML configs was tossed around by the devs many a time; however, no dev team so far has lasted long enough to implement it. Each team so far has re-written the core to how they wanted it, and how they thought it would work best, and then promissed XML setups. Now...on your app idea, what would the point be of creating a XML document just so you can convert it back to the old setup? Why not just write the step in the top down format and run with it? (Which btw is already done in at least one app.)