I got my VS 2005 package that does xpath syntax hilighting and hilighting of matched nodes working (in its most basic form) tonight. It uses some of the built-in text markers, doesn't show the context node etc, but its a start. And if you haven't wrangled with the VS API before don't even bother speculating how hard/easy this might be. I'm just doing my bit to try and advance the Xml Nation (esp point #1).
