Glad you like it. A great deal of the credit belongs to the lxml authors (Stephan Behnel in particular). Though this only took a day or do, I've been using lxml for projects for years and always loved it - in particular, the xpath makes modifying and querying trees really easy.

If more people used LXML and saw how easy it was, the whole idea of modifying serialized XML 'Cthulu style' would be seen as being as odd as modifying other data by manipulating their pickled forms.