I just got it to work with the 2.0.0beta release. In case you still need the information: You need to copy
libcroco-0.6.3.dll and
libgsf-1-114.dll
from the archive at
http://perisama.net/libs/gtk/gtk-2.10-runtime-full.zip
into your php-gtk2 directory.
Additionally, you will need a copy of bzip2.dll there. Version 1.0.3.1928 as reported by windows file properties works. You can get it from the Gimp 2.6 windows build for example. I've had no luck with newer (1.0.5) bzip2.dll libraries.
It also works with the 2.0.1 stable release but there are more files that need to be copied from the beta in addition to the above:
freetype6.dll
libfontconfig-1.dll
libexpat.dll
lib/gtk-2.0/2.10.0/loaders/libpixbufloader-svg.dll
etc/gtk-2.0/gdk-pixbuf.loaders
Hope this helps everybody trying to work with SVG and PHP-Gtk.
Regards, André