[dan]

You've got two problems

Your calling your loadmovie before your xml has loaded - so it's undefined.

You need to trigger this after the xml load has succeeded. Use a function call from within the onLoad handler...

Your in the right node but you're targeting the node itself not the url attribute.

something like

var featured_xml = new XML();
featured_xml.ignoreWhite = true;

featured_xml.onLoad = function(success){
	if (success) {
		imageIt();
		 trace(this);
 	}else{
		trace("Error loading XML file"); // no success? trace error (wont be seen on web)
 	};
};

// load
featured_xml.load("xml/fMovies.xml");

imageIt = function () {
	var featuredMovie = featured_xml.firstChild.childNodes;
        trace(featuredMovie);
        featured_mc.loadMovie(featuredMovie[0].attributes.url);
};

When writing things like this always use traces to see where you actually are in the node tree, it's hard to imagine sometimes.

Remember trace(); is your friend. Use it. LOTS.