I've started working on my WrapVTK project again, which aims to be a new wrapper-generator for VTK. This project started last spring as a test-bed for the "2010 VTK Wrapper Overhaul". Essentially, I coupled my revamped vtkParse wrapper-generator front end with an XML-generator back end, so that I could be certain that vtkParse was correctly parsing the VTK header files.
My big news is that I have updated the XML that WrapVTK produces. In the first iteration, it produced highly verbose XML output that was less readable than I liked. This time around, I put a lot of thought into how I could use attributes to make the XML more compact, without losing any flexibility. This is the result. At the same time, I did a few fixes to make sure that it will work with the upcoming VTK 5.8 release (the first VTK release with my new Python wrappers!)
Also, if anyone out there knows of any other XML file formats for describing C++ header files, can you send me a comment? The closest things I have been able to find in my searches are GCCXML, XML-RPC, and SOAP, none of which are really suitable for me. GCCXML is almost usable, except that it cannot provide information about unspecialized templates, and is lacking in human-readability and compactness.