I am looking for a command-line utility that could do:

    webpage2pdf 'http://bit-player.org/deck.js/limits-to-growth-Harvard-2012-03-30/ltg-talk.html#Lotka-Volterra' slide.pdf

and actually work (create a sensible PDF representation of what I can see in a browser). So my feedback wouldn't be useful, as my use case is out of scope for your project: "PyXML2PDF is NOT compatible with any XHTML/HTML/CSS. It uses a small set of tags to quickly allow generation of PDFs."