You should use pages.xml(/faces-config.xml) for stateless navigation, jpdl pageflows for stateful navigation. e.g. use pages.xml for crud, pageflow for a wizard.
..and limousyf - the visual faces-config.xml editor should still be there if you prefer that one.
but I was thinking of a visual editor for seam navigation, with conversation management, param management and finally get rid of those string-return methods !