Armin Ronacher is a stone cold badass. He created Flask: http://flask.pocoo.org/

In the section on the with statement he says

> Please don't abuse with for XML/HTML generation

Being guilty of such abuse, I would like to know why not? (I genuinely want to know!)

This is an example of why you should never use "new" in a title. This slide set is about Python 2.3's new features which are, at this point in time, old news. But the examples are still informative.