Tom Moertel and Bill Hubauer have cooked up PXSL, a shorthand notation for writing XML. PXSL is particularly targeted at XML documents that are heavier on the markup than on the text data. They pull the Python trick of using indentation to indicate nesting, break markup out of the angle brackets, and then force the text data into delimiters. They also have a macro system, based upon PL design principles, baked in.
Interesting stuff, and it actually looks like a better target for higher level tools than XML itself. Of course to my eye, they're simply trending towards s-exprs.