Eclipse noticed that updates were available. I let it go ahead and do some updates, whereupon the XML stuff all appeared in the menus and my Maven stuff disappeared! (The standard m2e connector.) I've not figured this one out yet, but at least I have the workaround of doing XML stuff in Eclipse and Maven stuff in Netbeans.
Cheers, Mark The University of Dundee is a registered Scottish Charity, No: SC015096