Hi,
I did something similar a very long time ago… Looking at it quickly now though I don’t have memory of it, but my documentation states something similar what you are looking for (god, time flies quickly and braincells get destroyed even quicker!)
http://dev.vaadin.com/svn/incubator/WizardWidget/
If my memory serves me correctly it chewed on an XML file which had some components defined in it so it was basically a demo of two things: 1) Wizard style UI and 2) dynamic XML driven UI creation